Methods of treatment using il-31ra

ABSTRACT

The present invention relates to methods of treating patients suffering from Contact dermatitis, Drug induced delayed type cutaneous allergic reactions, Toxic epidermal necrolysis, Cutaneous T cell Lymphoma, Bullous pemphigoid, Alopecia aereata, Vitiligo, Acne Rosacea, Prurigo nodularis, Scleroderma, Herpes simplex virus, or combination by administering an IL-31RA antagonist.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.12/404,162, filed Mar. 13, 2009, which is a continuation of U.S.application Ser. No. 11/353,451, filed Feb. 14, 2006, abandoned, whichclaims the benefit of U.S. Patent Application Ser. No. 60/716,761, filedSep. 13, 2005, U.S. Patent Application Ser. No. 60/694,867, filed Jun.29, 2005, and U.S. Patent Application Ser. No. 60/653,283, filed Feb.14, 2005, all of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

The skin plays an important role in the immune system and consists oflayers. The epidermis is a surface layer. Underneath the epidermis isthe dermis, a layer of connective tissue. Underneath the dermis, is thehypodermis, a layer of large amounts of adipose tissue. Circulating Tlymphocytes migrate to the skin under normal and inflammatoryconditions. The cutaneous lymphocyte antigen (CLA) is considered ahoming receptor for T cells with tropism for the skin. Santamaria-Babi,L., Eur. J. Dermatol. 14:13-18, 2004. CLA is a carbohydrate structurewhich is expressed on memory T cells as an epitope of the singlecell-surface protein named P-selectin glycoprotein ligand-1 (PSGL-1) andfacilitates binding of T cells to E-selectin, an inducible adhesionmolecule expressed on vascular endothelium. See Fuhlbrigge R C, et al.,Nature 1997; 389:978-81.

Several diseases of the skin are known to express high levels of CLA+ Tcells, including atopic dermatitis, contact dermatitis, drug-inducedallergic reactions, skin-tropic viruses and viral associated pruritis,vitiligo, cutaneous T cell lymphoma, alopecia aerata, acne rosacea, acnevulgaris, prurigo nodularis, and bullous pemphigoid. There is a need totreat such skin T cell mediated diseases.

The demonstrated in vivo activities of the cytokine family illustratethe enormous clinical potential of, and need for, other cytokines,cytokine agonists, and cytokine antagonists. The present inventionaddresses these needs by providing a method of treating such diseaseswith IL-31RA antagonists, e.g., IL-31RA soluble receptor or neutralizingIL-31RA monoclonal antibody or fragment, a receptor for the newlyidentified IL-31 cytokine. IL-31, when over-expressed in mice, resultsin dermatitis-like symptoms. Both skin-homing T cells and epidermalkeratinocytes have been implicated in the pathology of skin diseases inhumans.

The present invention provides such polypeptides for these and otheruses that should be apparent to those skilled in the art from theteachings herein.

DETAILED DESCRIPTION OF THE INVENTION Definitions

Prior to setting forth the invention in detail, it may be helpful to theunderstanding thereof to define the following terms:

Unless otherwise specified, “a,” “an,” “the,” and “at least one” areused interchangeably and mean one or more than one.

The term “affinity tag” is used herein to denote a polypeptide segmentthat can be attached to a second polypeptide to provide for purificationor detection of the second polypeptide or provide sites for attachmentof the second polypeptide to a substrate. In principal, any peptide orprotein for which an antibody or other specific binding agent isavailable can be used as an affinity tag. Affinity tags include apoly-histidine tract, protein A (Nilsson et al., EMBO J. 4:1075, 1985;Nilsson et al., Methods Enzymol. 198:3, 1991), glutathione S transferase(Smith and Johnson, Gene 67:31, 1988), Glu-Glu affinity tag(Grussenmeyer et al., Proc. Natl. Acad. Sci. USA 82:7952-4, 1985),substance P, Flag™ peptide (Hopp et al., Biotechnology 6:1204-10, 1988),streptavidin binding peptide, or other antigenic epitope or bindingdomain. See, in general, Ford et al., Protein Expression andPurification 2: 95-107, 1991. DNAs encoding affinity tags are availablefrom commercial suppliers (e.g., Pharmacia Biotech, Piscataway, N.J.).

The term “allelic variant” is used herein to denote any of two or morealternative forms of a gene occupying the same chromosomal locus.Allelic variation arises naturally through mutation, and may result inphenotypic polymorphism within populations. Gene mutations can be silent(no change in the encoded polypeptide) or may encode polypeptides havingaltered amino acid sequence. The term allelic variant is also usedherein to denote a protein encoded by an allelic variant of a gene.

The terms “amino-terminal” and “carboxyl-terminal” are used herein todenote positions within polypeptides. Where the context allows, theseterms are used with reference to a particular sequence or portion of apolypeptide to denote proximity or relative position. For example, acertain sequence positioned carboxyl-terminal to a reference sequencewithin a polypeptide is located proximal to the carboxyl terminus of thereference sequence, but is not necessarily at the carboxyl terminus ofthe complete polypeptide.

The term “complement/anti-complement pair” denotes non-identicalmoieties that form a non-covalently associated, stable pair underappropriate conditions. For instance, biotin and avidin (orstreptavidin) are prototypical members of a complement/anti-complementpair. Other exemplary complement/anti-complement pairs includereceptor/ligand pairs, antibody/antigen (or hapten or epitope) pairs,sense/antisense polynucleotide pairs, and the like. Where subsequentdissociation of the complement/anti-complement pair is desirable, thecomplement/anti-complement pair preferably has a binding affinity of<10⁹ M⁻¹.

The term “complements of a polynucleotide molecule” denotes apolynucleotide molecule having a complementary base sequence and reverseorientation as compared to a reference sequence. For example, thesequence 5′ ATGCACGGG 3′ is complementary to 5′ CCCGTGCAT 3′.

The term “contig” denotes a polynucleotide that has a contiguous stretchof identical or complementary sequence to another polynucleotide.Contiguous sequences are said to “overlap” a given stretch ofpolynucleotide sequence either in their entirety or along a partialstretch of the polynucleotide. For example, representative contigs tothe polynucleotide sequence 5′-ATGGCTTAGCTT-3′ (SEQ ID NO:18) are5′-TAGCTTgagtct-3′ (SEQ ID NO:19) and 3′-gtcgacTACCGA-5′ (SEQ ID NO:20).

The term “degenerate nucleotide sequence” denotes a sequence ofnucleotides that includes one or more degenerate codons (as compared toa reference polynucleotide molecule that encodes a polypeptide).Degenerate codons contain different triplets of nucleotides, but encodethe same amino acid residue (i.e., GAU and GAC triplets each encodeAsp).

The term “expression vector” is used to denote a DNA molecule, linear orcircular, that comprises a segment encoding a polypeptide of interestoperably linked to additional segments that provide for itstranscription. Such additional segments include promoter and terminatorsequences, and may also include one or more origins of replication, oneor more selectable markers, an enhancer, a polyadenylation signal, etc.Expression vectors are generally derived from plasmid or viral DNA, ormay contain elements of both.

The term “isolated”, when applied to a polynucleotide, denotes that thepolynucleotide has been removed from its natural genetic milieu and isthus free of other extraneous or unwanted coding sequences, and is in aform suitable for use within genetically engineered protein productionsystems. Such isolated molecules are those that are separated from theirnatural environment and include cDNA and genomic clones. Isolated DNAmolecules of the present invention are free of other genes with whichthey are ordinarily associated, but may include naturally occurring 5′and 3′ untranslated regions such as promoters and terminators. Theidentification of associated regions will be evident to one of ordinaryskill in the art (see for example, Dynan and Tijan, Nature 316:774-78,1985).

An “isolated” polypeptide or protein is a polypeptide or protein that isfound in a condition other than its native environment, such as apartfrom blood and animal tissue. In a preferred form, the isolatedpolypeptide is substantially free of other polypeptides, particularlyother polypeptides of animal origin. It is preferred to provide thepolypeptides in a highly purified form, i.e. greater than 95% pure, morepreferably greater than 99% pure. When used in this context, the term“isolated” does not exclude the presence of the same polypeptide inalternative physical forms, such as dimers or alternatively glycosylatedor derivatized forms.

The term “operably linked”, when referring to DNA segments, indicatesthat the segments are arranged so that they function in concert fortheir intended purposes, e.g., transcription initiates in the promoterand proceeds through the coding segment to the terminator.

The term “ortholog” denotes a polypeptide or protein obtained from onespecies that is the functional counterpart of a polypeptide or proteinfrom a different species. Sequence differences among orthologs are theresult of speciation.

“Paralogs” are distinct but structurally related proteins made by anorganism. Paralogs are believed to arise through gene duplication. Forexample, α-globin, β-globin, and myoglobin are paralogs of each other.

A “polynucleotide” is a single- or double-stranded polymer ofdeoxyribonucleotide or ribonucleotide bases read from the 5′ to the 3′end. Polynucleotides include RNA and DNA, and may be isolated fromnatural sources, synthesized in vitro, or prepared from a combination ofnatural and synthetic molecules. Sizes of polynucleotides are expressedas base pairs (abbreviated “bp”), nucleotides (“nt”), or kilobases(“kb”). Where the context allows, the latter two terms may describepolynucleotides that are single-stranded or double-stranded. When theterm is applied to double-stranded molecules it is used to denoteoverall length and will be understood to be equivalent to the term “basepairs”. It will be recognized by those skilled in the art that the twostrands of a double-stranded polynucleotide may differ slightly inlength and that the ends thereof may be staggered as a result ofenzymatic cleavage; thus all nucleotides within a double-strandedpolynucleotide molecule may not be paired.

A “polypeptide” is a polymer of amino acid residues joined by peptidebonds, whether produced naturally or synthetically. Polypeptides of lessthan about 10 amino acid residues are commonly referred to as“peptides”.

The term “promoter” is used herein for its art-recognized meaning todenote a portion of a gene containing DNA sequences that provide for thebinding of RNA polymerase and initiation of transcription. Promotersequences are commonly, but not always, found in the 5′ non-codingregions of genes.

A “protein” is a macromolecule comprising one or more polypeptidechains. A protein may also comprise non-peptidic components, such ascarbohydrate groups. Carbohydrates and other non-peptidic substituentsmay be added to a protein by the cell in which the protein is produced,and will vary with the type of cell. Proteins are defined herein interms of their amino acid backbone structures; substituents such ascarbohydrate groups are generally not specified, but may be presentnonetheless.

The term “receptor” denotes a cell-associated protein that binds to abioactive molecule (i.e., a ligand) and mediates the effect of theligand on the cell. Membrane-bound receptors are characterized by amulti-peptide structure comprising an extracellular ligand-bindingdomain and an intracellular effector domain that is typically involvedin signal transduction. Binding of ligand to receptor results in aconformational change in the receptor that causes an interaction betweenthe effector domain and other molecule(s) in the cell. This interactionin turn leads to an alteration in the metabolism of the cell. Metabolicevents that are linked to receptor-ligand interactions include genetranscription, phosphorylation, dephosphorylation, increases in cyclicAMP production, mobilization of cellular calcium, mobilization ofmembrane lipids, cell adhesion, hydrolysis of inositol lipids andhydrolysis of phospholipids. In general, receptors can be membranebound, cytosolic or nuclear; monomeric (e.g., thyroid stimulatinghormone receptor, beta-adrenergic receptor) or multimeric (e.g., PDGFreceptor, growth hormone receptor, IL-3 receptor, GM-CSF receptor, G-CSFreceptor, erythropoietin receptor and IL-6 receptor).

The term “secretory signal sequence” denotes a DNA sequence that encodesa polypeptide (a “secretory peptide”) that, as a component of a largerpolypeptide, directs the larger polypeptide through a secretory pathwayof a cell in which it is synthesized. The larger polypeptide is commonlycleaved to remove the secretory peptide during transit through thesecretory pathway.

A “soluble receptor” is a receptor polypeptide that is not bound to acell membrane. Soluble receptors are most commonly ligand-bindingreceptor polypeptides that lack transmembrane and cytoplasmic domains.Soluble receptors can comprise additional amino acid residues, such asaffinity tags that provide for purification of the polypeptide orprovide sites for attachment of the polypeptide to a substrate, orimmunoglobulin constant region sequences. Many cell-surface receptorshave naturally occurring, soluble counterparts that are produced byproteolysis. Soluble receptor polypeptides are said to be substantiallyfree of transmembrane and intracellular polypeptide segments when theylack sufficient portions of these segments to provide membrane anchoringor signal transduction, respectively.

The term “splice variant” is used herein to denote alternative forms ofRNA transcribed from a gene. Splice variation arises naturally throughuse of alternative splicing sites within a transcribed RNA molecule, orless commonly between separately transcribed RNA molecules, and mayresult in several mRNAs transcribed from the same gene. Splice variantsmay encode polypeptides having altered amino acid sequence. The termsplice variant is also used herein to denote a protein encoded by asplice variant of an mRNA transcribed from a gene.

Molecular weights and lengths of polymers determined by impreciseanalytical methods (e.g., gel electrophoresis) will be understood to beapproximate values. When such a value is expressed as “about” X or“approximately” X, the stated value of X will be understood to beaccurate to ±10%.

All references cited herein are incorporated by reference in theirentirety.

The present invention provides novel methods of using IL-31RAantagonists in detection, diagnosis, and treatment of diseases, inparticular, diseases that have a high correlation of cutaneouslymphocyte antigen (CLA). The present invention is based in part uponthe discovery that a previously identified cytokine, IL-31 is expressedby skin-homing T cells, but not gut-homing T cells.

IL-31 is a recently discovered protein having the structure of afour-helical-bundle cytokine. This cytokine was previously identified asIL-31 and is fully described in U.S. patent application Ser. No.10/352,554, filed Jan. 21, 2003. See published U.S. Patent ApplicationNo. 2003-0224487, and PCT application WO 03/060090, all hereinincorporated by reference. See also, Dillon, et al., Nature Immunol.5:752-760, 2004. IL-31 is a ligand with high specificity for thereceptor IL-31RA and at least one additional subunit comprisingOncostatinM receptor beta (OSMRbeta). The native polynucleotide andpolypeptide sequences for human IL-31 are shown in SEQ ID NOs:1 and 2,respectively. The native polynucleotide and polypeptide sequences formouse IL-31 are shown in SEQ ID NOs:3 and 4, respectively.

As used herein the term, IL-31 also means and is interchangeablyreferred to as Zcytor17 μg, and IL-31RA also means and isinterchangeably referred to as Zcytor17, as used in U.S. patentpublication number 20030224487 (herein incorporated by reference), asshown above. The heterodimeric receptor for IL-31 was also described in20030224487 as comprising zcytor17 (HUGO name, IL-31RA) and with atleast one additional subunit comprising OncostatinM receptor beta(OSMRbeta).

The native polynucleotide and polypeptide sequences for the “long” formof IL-31RA are shown in SEQ ID NOs:5 and 6, respectively. The nativepolynucleotide and polypeptide sequences for the “short” form of IL-31RAare shown in SEQ ID NOs:7 and 8, respectively. Additionally, truncatedforms of IL-31RA polypeptide appear to be naturally expressed. Bothforms encode soluble IL-31RA receptors. The “long” soluble IL-31RApolynucleotide and polypeptide sequences are shown in SEQ ID NOs:9 and10, respectively. The “short” soluble IL-31RA polynucleotide andpolypeptide sequences are shown in SEQ ID NOs:11 and 12, respectively.The native polynucleotide and polypeptide sequences for mouse IL-31RAare shown in SEQ ID NOs:13 and 14, respectively. The nativepolynucleotide and polypeptide sequences for human OSMRbeta are shown inSEQ ID NOs:15 and 16, respectively. See PCT applications WO 02/00721 andWO 04/003140, both of which are incorporated by reference.

The secretory signal sequence of IL-31 is comprised of amino acidresidues 1 (Met) to 23 (Ala), and the mature polypeptide is comprised ofamino acid residues 24 (Ser) to 164 (Thr) as shown in SEQ ID NO:2.Further N-terminal sequencing analysis of purified IL-31 from 293T cellsshowed an N-terminus at residue 27 (Leu) as shown in SEQ ID NO:2, withthe mature polypeptide comprised of amino acid residues 27 (Leu) to 164(Thr) as shown in SEQ ID NO:2.

Cytokine receptor subunits are characterized by a multi-domain structurecomprising an extracellular domain, a transmembrane domain that anchorsthe polypeptide in the cell membrane, and an intracellular domain. Theextracellular domain may be a ligand-binding domain, and theintracellular domain may be an effector domain involved in signaltransduction, although ligand-binding and effector functions may resideon separate subunits of a multimeric receptor. The domains andstructural features of the IL-31RA polypeptides (zcytor17) are furtherdescribed below.

Analysis of the IL-31RA polypeptide encoded by the DNA sequence of SEQID NO:5 revealed an open reading frame encoding 732 amino acids (SEQ IDNO:6) comprising a predicted secretory signal peptide of 19 amino acidresidues (residue 1 (Met) to residue 19 (Ala) of SEQ ID NO:6), and amature polypeptide of 713 amino acids (residue 20 (Ala) to residue 732(Val) of SEQ ID NO:6). Analysis of the IL-31RA polypeptide encoded bythe DNA sequence of SEQ ID NO:7 revealed an open reading frame encoding662 amino acids (SEQ ID NO:8) comprising a predicted secretory signalpeptide of 32 amino acid residues (residue 1 (Met) to residue 32 (Ala)of SEQ ID NO:8), and a mature polypeptide of 630 amino acids (residue 33(Ala) to residue 662 (Ile) of SEQ ID NO:8). In addition to the WSXWSmotif (SEQ ID NO:17) (corresponding to residues 211 to 215 of SEQ IDNO:6; and residues 224 to 228 of SEQ ID NO:8), the receptor comprises anextracellular domain (residues 20 (Ala) to 519 (Glu) of SEQ ID NO:6;residues 33 (Ala) to 532 (Glu) of SEQ ID NO:8) which includes acytokine-binding domain of approximately 200 amino acid residues(residues 20 (Ala) to 227 (Pro) of SEQ ID NO:6; residues 33 (Ala) to 240(Pro) of SEQ ID NO:8); a domain linker (residues 122 (Thr) to 125 (Pro)of SEQ ID NO:6; residues 135 (Thr) to 138 (Pro) of SEQ ID NO:8); apenultimate strand region (residues 194 (Phe) to 202 (Arg) of SEQ IDNO:6; residues 207 (Phe) to 215 (Arg) of SEQ ID NO:8); a fibronectintype III domain (residues 228 (Cys) to 519 (Glu) of SEQ ID NO:6;residues 241 (Cys) to 532 (Glu) of SEQ ID NO:8); a transmembrane domain(residues 520 (Ile) to 543 (Leu) of SEQ ID NO:6; residues 533 (Ile) to556 (Leu) of SEQ ID NO:8); complete intracellular signaling domain(residues 544 (Lys) to 732 (Val) of SEQ ID NO:6; and residues 557 (Lys)to 662 (Ile) of SEQ ID NO:8) which contains a “Box I” signaling site(residues 554 (Trp) to 560 (Pro) of SEQ ID NO:6; residues 567 (Trp) to573 (Pro) of SEQ ID NO:8), and a “Box II” signaling site (residues 617(Gln) to 620 (Phe) of SEQ ID NO:6; residues 630 (Gln) to 633 (Phe) ofSEQ ID NO:8). Those skilled in the art will recognize that these domainboundaries are approximate, and are based on alignments with knownproteins and predictions of protein folding. In addition to thesedomains, conserved receptor features in the encoded receptor include (asshown in SEQ ID NO:6) a conserved Cys residue at position 30 (position43 as shown in SEQ ID NO:8), CXW motif (wherein X is any amino acid) atpositions 40-42 of SEQ ID NO:6 (positions 53-55 as shown in SEQ IDNO:8), Trp residue at position 170 of SEQ ID NO:6 (position 183 as shownin SEQ ID NO:8), and a conserved Arg residue at position 202 of SEQ IDNO:6 (position 215 as shown in SEQ ID NO:8). The correspondingpolynucleotides encoding the IL-31RA polypeptide regions, domains,motifs, residues and sequences described above are as shown in SEQ IDNOs:5 and 7.

Moreover, truncated forms of the IL-31RA polypeptide appear to benaturally expressed. Both forms encode soluble zcytor17 receptors. Apolynucleotide encoding a “long-form” of the soluble zcytor17 receptor,truncated within the fibronectin type III domain, is shown in SEQ IDNO:9 and the corresponding polypeptide is shown in SEQ ID NO:10. Thistruncated form encodes residues 1 (Met) through 324 (Lys) of SEQ IDNO:6, and thus comprises an intact signal sequence, WSXWS (SEQ ID NO:17)motif, linker, cytokine binding domain, penultimate strand, andconserved, Cys, CXW motif, Trp and Arg residues as described above. Apolynucleotide encoding a “short-form” of the soluble IL-31RA receptor,truncated at the end of the cytokine binding domain is shown in SEQ IDNO:11 and the corresponding polypeptide is shown in SEQ ID NO:12. Thistruncated form encodes a 239 residue polypeptide that is identical toresidues 1 (Met) through 225 (Glu) of SEQ ID NO:6 and then diverges, andthus comprises an intact signal sequence, WSXWS (SEQ ID NO:17) motif,linker, cytokine binding domain, penultimate strand, and conserved, Cys,CXW motif, Trp and Arg residues as described above.

Both skin-homing T cells and epidermal keratinocytes have beenimplicated in the pathology of skin diseases in humans. As shown herein,IL-31 mRNA and protein expression is restricted to the skin-homing CLA+T cell population in both atopic dermatitis (AD) patients and normalindividuals, while analysis of the receptor for IL-31, IL-31RA, byimmunohistochemistry (IHC) suggests slightly higher levels of IL-31RAexpression on skin keratinocytes in skin biopsies from acute and chronicAD sufferers compared to normal individuals.

When over-expressed in mice, IL-31 results in pruritus and thedevelopment of skin dermatitis resembling human atopic dermatitis (AD)Immunohistochemistry (IHC) studies shown herein show that IL-31RAprotein was expressed by skin keratinocytes and infiltrating macrophagesin skin biopsies from AD patients. Comparisons between AD patients andnormal individuals suggested that IL-31RA was expressed at higher levelson epidermal keratinocytes in the AD samples. Skin cell infiltrates,which were present at greater numbers in skin of AD patients compared tonormal individuals, expressed IL-31 mRNA. Histomorphometric analysis ofthese cells suggested a lymphocytic lineage with the majority of cellsstaining positive for cutaneous lymphocyte antigen (CLA) and CD3,demonstrating that skin-homing T cells in skin express IL-31 mRNA. Uponanalysis of peripheral blood T cells for IL-31, IL-31 mRNA and proteinexpression is largely restricted to CD45RO+ CLA+ skin-homing T cells inAD and normal volunteers. Moreover, circulating CLA+ T cells from ADpatients are capable of producing higher levels of IL-31 compared toCLA+ T cells from normal individuals, though there is large variabilitybetween patient samples. These results provide strong evidence thatIL-31 expression is associated with atopic dermatitis and may contributeto the development of AD skin inflammation and pruritus.

As shown herein, IL-31 is produced both locally in the skin and by skininfiltrating cells. Local production of cytokines in tissues by T cellsis thought to be a key mechanism for disease pathogenesis in AD andincreased numbers of T cells both in circulation and in skin is thoughtto correlate with disease.

Although both AD patients and normal controls have circulating CLA+ Tcells that express IL-31 upon activation, CLA+ T cells from AD patientsare reported to exist in a more activated state compared to cells fromnormal individuals. See Akdis M, J Immunol., 159:4611-4619, 1997.Consequently, the threshold of stimulation required for the productionof IL-31 by CLA+ T cells may differ between dermatitis patients andcontrol subjects. As shown herein, circulating CLA+ T cells from ADpatients after 24 hours of stimulation with sub-optimal concentrationsof anti-CD3 in the absence of anti-CD28 have the capacity to producehigher levels of IL-31 compared to cells from normal individuals. Due tothe variability in IL-31 levels produced by CLA+ T cells from individualAD patients, there was no significant difference in the average IL-31production from circulating CLA+ T cells of AD and normal individuals.Nevertheless, since more CLA+ T cells are localized in skin of ADpatients, as compared to normal individuals, there is an increasedpotential for IL-31 activity in the AD skin micro-environment.

Example 1 demonstrates that circulating CLA+ T cells from some ADpatients produce higher levels of IL-31 compared to cells from normalindividuals. The detection of IL-31 in patients of such a subpopulationusing the bioassay provided herein, or with any assay that detects IL-31produced by circulating T cells in the blood, may be useful to determineif an IL-31 antagonist will be useful as treatment for diseases whereinthe presence of IL-31 causes inflammation.

A cell line that is dependent on the OSMRbeta and IL-31RA linked pathwayfor survival and growth in the absence of other growth factors can beused to measure the activity of IL-31. Such growth factor-dependent celllines include BaF3, FDC-P1, and MO7e. For information on the BaF3 cellline, see Palacios and Steinmetz, (Cell, 41:727-734, 1985) andMathey-Prevot et al., (Mol. Cell. Biol., 6:4133-4135, 1986). Forinformation on the FDC-P 1 cell line, see Hapel et al. (Blood,64:786-790, 1984). For information on the MO7e cell line, see Kiss etal., (Leukemia, 7:235-240, 1993).

The amino acid sequence for the OSMRbeta, and IL-31RA receptorsindicated that the encoded receptors belonged to the Class I cytokinereceptor subfamily that includes, but is not limited to, the receptorsfor IL-2, IL-4, IL-7, Lif, IL-12, IL-15, EPO, TPO, GM-CSF and G-CSF (fora review see, Cosman, “The Hematopoietin Receptor Superfamily” inCytokine 5(2): 95-106, 1993). The IL-31RA receptor is fully described inPCT Patent Application No. US01/20484 (WIPO publication No. WO02/00721). Analysis of the tissue distribution of the mRNA of theIL-31RA receptor revealed expression in activated CD4+ and CD8+ T-cellsubsets, CD14+ monocytes, and weaker expression in CD19+ B-cells.Moreover, the mRNA was present in both resting or activated monocyticcell lines THP-1 (ATCC No. TIB-202), U937 (ATCC No. CRL-1593.2) and HL60(ATCC No. CCL-240).

Antigenic epitope-bearing peptides and polypeptides preferably containat least four to ten amino acids, at least ten to fourteen amino acids,or about fourteen to about thirty amino acids of the extracellulardomains of SEQ ID NO:6 or SEQ ID NO:8. Such epitope-bearing peptides andpolypeptides can be produced by fragmenting the extracellular domain ofIL-31RA polypeptide, or by chemical peptide synthesis, as describedherein. Moreover, epitopes can be selected by phage display of randompeptide libraries (see, for example, Lane and Stephen, Curr. Opin.Immunol 5:268 (1993); and Cortese et al., Curr. Opin. Biotechnol. 7:616(1996)). Standard methods for identifying epitopes and producingantibodies from small peptides that comprise an epitope are described,for example, by Mole, “Epitope Mapping,” in Methods in MolecularBiology, Vol. 10, Manson (ed.), pages 105-116 (The Humana Press, Inc.1992); Price, “Production and Characterization of SyntheticPeptide-Derived Antibodies,” in Monoclonal Antibodies: Production,Engineering, and Clinical Application, Ritter and Ladyman (eds.), pages60-84 (Cambridge University Press 1995), and Coligan et al. (eds.),Current Protocols in Immunology, pages 9.3.1-9.3.5 and pages9.4.1-9.4.11 (John Wiley & Sons 1997).

The IL-31RA polypeptides of the present invention, including full-lengthpolypeptides, functional fragments, and fusion polypeptides, can beproduced, purified and refolded by methods well-known in the art and asdescribed in PCT applications WO 02/00721 and WO 04/003140. It ispreferred to purify the polypeptides of the present invention to ≧80%purity, more preferably to ≧90% purity, even more preferably ≧95%purity, and particularly preferred is a pharmaceutically pure state,that is greater than 99.9% pure with respect to contaminatingmacromolecules, particularly other proteins and nucleic acids, and freeof infectious and pyrogenic agents. Preferably, a purified polypeptideis substantially free of other polypeptides, particularly otherpolypeptides of animal origin.

The present invention provides methods for using IL-31RA antagonists,including anti-IL-31RA antibodies and fragments, soluble IL-31RAreceptors, and soluble IL-31RA/OSMRbeta receptors for reducing,inhibiting, or preventing inflammation in cell microenvironments whereone or more cells in the microenvironment is/are T cells that arepositive for the cutaneous lymphocyte antigen.

Antibodies from an immune response generated by inoculation of an animalwith IL-31RA antigens, e.g., extracellular domain of SEQ ID NO:6 or aportion thereof, such as ligand binding domain) can be isolated andpurified are known in the art and are described herein. Methods forpreparing and isolating polyclonal and monoclonal antibodies are wellknown in the art. See, for example, Current Protocols in Immunology,Cooligan, et al. (eds.), National Institutes of Health, John Wiley andSons, Inc., 1995; Sambrook et al., Molecular Cloning: A LaboratoryManual, Second Edition, Cold Spring Harbor, N.Y., 1989; and Hurrell, J.G. R., Ed., Monoclonal Hybridoma Antibodies: Techniques andApplications, CRC Press, Inc., Boca Raton, Fla., 1982.

As would be evident to one of ordinary skill in the art, polyclonalantibodies can be generated from inoculating a variety of warm-bloodedanimals such as horses, cows, goats, sheep, dogs, chickens, rabbits,mice, and rats with a IL-31RA polypeptide or a fragment thereof. Theimmunogenicity of an IL-31RA polypeptide may be increased through theuse of an adjuvant, such as alum (aluminum hydroxide) or Freund'scomplete or incomplete adjuvant. Polypeptides useful for immunizationalso include fusion polypeptides, such as fusions of IL-31RA or aportion thereof with an immunoglobulin polypeptide or with maltosebinding protein. The polypeptide immunogen may be a full-length moleculeor a portion thereof. If the polypeptide portion is “hapten-like”, suchportion may be advantageously joined or linked to a macromolecularcarrier (such as keyhole limpet hemocyanin (KLH), bovine serum albumin(BSA) or tetanus toxoid) for immunization.

As used herein, the term “antibodies” includes polyclonal antibodies,affinity-purified polyclonal antibodies, monoclonal antibodies, andantigen-binding fragments, such as Fab fragment, Fab′ fragment, F(ab′)₂fragment, single chain Fv (scFv) proteolytic fragments. Geneticallyengineered intact antibodies or fragments, such as chimeric antibodies,Fv fragments, single chain antibodies and the like, as well as syntheticantigen-binding peptides and polypeptides, are also included. Non-humanantibodies may be humanized by grafting non-human CDRs onto humanframework and constant regions, or by incorporating the entire non-humanvariable domains (optionally “cloaking” them with a human-like surfaceby replacement of exposed residues, wherein the result is a “veneered”antibody). In some instances, humanized antibodies may retain non-humanresidues within the human variable region framework domains to enhanceproper binding characteristics. Through humanizing antibodies,biological half-life may be increased, and the potential for adverseimmune reactions upon administration to humans is reduced. Moreover,human antibodies can be produced in transgenic, non-human animals thathave been engineered to contain human immunoglobulin genes as disclosedin WIPO Publication No. WO 98/24893. It is preferred that the endogenousimmunoglobulin genes in these animals be inactivated or eliminated, suchas by homologous recombination.

Antibodies are considered to be specifically binding if: 1) they exhibita threshold level of binding activity, and 2) they do not significantlycross-react with related polypeptide molecules. A threshold level ofbinding is determined if anti-IL-31RA antibodies herein bind to anIL-31RA polypeptide, peptide or epitope with an affinity at least10-fold greater than the binding affinity to control (non-IL-31RA)polypeptide. It is preferred that the antibodies exhibit a bindingaffinity (Ka) of 10⁶ M-1 or greater, preferably 10⁷ M-1 or greater, morepreferably 108 M-1 or greater, and most preferably 10⁹ M-1 or greater.The binding affinity of an antibody can be readily determined by one ofordinary skill in the art, for example, by Scatchard analysis(Scatchard, G., Ann. NY Acad. Sci. 51: 660-672, 1949).

The present invention provides a method of treating a patient sufferingfrom a skin disorder, the method comprises administering atherapeutically effective amount of an anti-IL-31RA antibody or fragmentto the patient, wherein the anti-IL-31RA antibody or fragment binds withamino acid residues 20-519 of SEQ ID NO:6 or portion thereof, or aminoacid residues 33-532 of SEQ ID NO:8 or portion thereof, and wherein theanti-IL-31RA antibody or fragment prevents, inhibits the progression of,delays the onset of, reduces the severity of, and/or inhibits at leastone of the conditions or symptoms of the skin disorder selected from thegroup consisting of Atopic Dermititis, Contact dermatitis, Drug induceddelayed type cutaneous allergic reactions, Toxic epidermal necrolysis,Cutaneous T cell Lymphoma, Bullous pemphigoid, Alopecia aereata,Vitiligo, Acne Rosacea, Prurigo nodularis, Scleroderma, and Herpessimplex virus. The anti-IL-31RA antibody may optionally be a polyclonalantibody or a neutralizing monoclonal antibody (the present inventionalso provides for a hybridoma for producing the neutralizing IL-31RAmonoclonal antibody). The anti-IL-31RA antibody fragment may optionallybe a Fab fragment, a Fab′ fragment, a F(ab′)2 fragment, single chain Fv(scFV), dual specific antibody, domain antibody, or bispecific antibody.The anti-IL-31RA antibody or fragment may bind with amino acid residues20-277 of SEQ ID NO:6 or 33-240 of SEQ ID NO:8. The anti-IL-31RAantibody or fragment may bind with about 4-10 amino acid residues ofamino acid residues 20-519 of SEQ ID NO:6 or amino acid residues 33-532of SEQ ID NO:8. The anti-IL-31RA antibody or fragment may bind withabout 10-14 amino acid residues of amino acid residues 20-519 of SEQ IDNO:6 or amino acid residues 33-532 of SEQ ID NO:8. The anti-IL-31RAantibody or fragment may bind with about 14-30 amino acid residues ofamino acid residues 20-519 of SEQ ID NO:6 or amino acid residues 33-532of SEQ ID NO:8. The anti-IL-31 antibody or fragment may be furtherconjugated to a polyethylene glycol or to human serum albumin.

The present invention also provides for a method of treating a patientsuffering from a skin disorder, the method comprises administering atherapeutically effective amount of a soluble IL-31RA receptor to thepatient, wherein the soluble IL-31RA receptor binds with an IL-31polypeptide consisting of amino acid residues 1-164 SEQ ID NO:2, andwherein the soluble IL-31RA receptor prevents, inhibits the progressionof, delays the onset of, reduces the severity of, and/or inhibits atleast one of the conditions or symptoms of the skin disorder selectedfrom the group consisting of Atopic Dermititis, Contact dermatitis, Druginduced delayed type cutaneous allergic reactions, Toxic epidermalnecrolysis, Cutaneous T cell Lymphoma, Bullous pemphigoid, Alopeciaaereata, Vitiligo, Acne Rosacea, Prurigo nodularis, Scleroderma, andHerpes simplex virus. The soluble IL-31RA receptor may comprise aminoacid residues 20-519 of SEQ ID NO:6 or 33-240 of SEQ ID NO:8, amino acidresidues 1-324 of SEQ ID NO:10, or amino acid residues 1-239 of SEQ IDNO:12. The soluble IL-31RA receptor may be further conjugated to the Fcregion of the various immunoglobulins (IgG, IgA, IgD, IgM or IgE).Optionally, the soluble IL-31RA receptor may be an IL-31RA homodimer oran IL-31RA/OSMRbeta heterodimer. The soluble IL-31RA receptor may bindwith an IL-31 polypeptide comprising, consisting essentially of,consisting of amino acid residues 24-164 of SEQ ID NO:2 or 27-164 of SEQID NO:2. The soluble IL-31RA receptor may be further conjugated to apolyethylene glycol or to human serum albumin.

The present invention also provides isolated IL-31RA encoding nucleicacid molecules that can hybridize under stringent conditions to nucleicacid molecules having the nucleotide sequence of nucleotides 58-1557 ofSEQ ID NO:5 or nucleotides 97-1596 SEQ ID NO:7, or to nucleic acidmolecules having a nucleotide sequence complementary to nucleotides58-1557 of SEQ ID NO:5 or to nucleotides 97-1596 SEQ ID NO:7. Ingeneral, stringent conditions are selected to be about 5*C lower thanthe thermal melting point (Tm) for the specific sequence at a definedionic strength and pH. The Tm is the temperature (under defined ionicstrength and pH) at which 50% of the target sequence hybridizes to aperfectly matched probe.

A pair of nucleic acid molecules, such as DNA-DNA, RNA-RNA and DNA-RNA,can hybridize if the nucleotide sequences have some degree ofcomplementarity. Hybrids can tolerate mismatched base pairs in thedouble helix, but the stability of the hybrid is influenced by thedegree of mismatch. The Tm of the mismatched hybrid decreases by 1° C.for every 1-1.5% base pair mismatch. Varying the stringency of thehybridization conditions allows control over the degree of mismatch thatwill be present in the hybrid. The degree of stringency increases as thehybridization temperature increases and the ionic strength of thehybridization buffer decreases.

It is well within the abilities of one skilled in the art to adapt theseconditions for use with a particular polynucleotide hybrid. The Tm for aspecific target sequence is the temperature (under defined conditions)at which 50% of the target sequence will hybridize to a perfectlymatched probe sequence. Those conditions which influence the Tm include,the size and base pair content of the polynucleotide probe, the ionicstrength of the hybridization solution, and the presence ofdestabilizing agents in the hybridization solution. Numerous equationsfor calculating Tm are known in the art, and are specific for DNA, RNAand DNA-RNA hybrids and polynucleotide probe sequences of varying length(see, for example, Sambrook et al., Molecular Cloning: A LaboratoryManual, Second Edition (Cold Spring Harbor Press 1989); Ausubel et al.,(eds.), Current Protocols in Molecular Biology (John Wiley and Sons,Inc. 1987); Berger and Kimmel (eds.), Guide to Molecular CloningTechniques, (Academic Press, Inc. 1987); and Wetmur, Crit. Rev. Biochem.Mol. Biol. 26:227 (1990)). Sequence analysis software such as OLIGO 6.0(LSR; Long Lake, Minn.) and Primer Premier 4.0 (Premier BiosoftInternational; Palo Alto, Calif.), as well as sites on the Internet, areavailable tools for analyzing a given sequence and calculating Tm basedon user defined criteria. Such programs can also analyze a givensequence under defined conditions and identify suitable probe sequences.Typically, hybridization of longer polynucleotide sequences, >50 basepairs, is performed at temperatures of about 20-25° C. below thecalculated Tm. For smaller probes, <50 base pairs, hybridization istypically carried out at the Tm or 5-10° C. below the calculated Tm.This allows for the maximum rate of hybridization for DNA-DNA andDNA-RNA hybrids.

Following hybridization, the nucleic acid molecules can be washed toremove non-hybridized nucleic acid molecules under stringent conditions,or under highly stringent conditions. Typical stringent washingconditions include washing in a solution of 0.5×-2×SSC with 0.1% sodiumdodecyl sulfate (SDS) at 55-65° C. That is, nucleic acid moleculesencoding a variant IL-31RA polypeptide hybridize with a nucleic acidmolecule having the nucleotide sequence of nucleotides 58-1557 of SEQ IDNO:5 (or its complement) or nucleotides 97-1596 SEQ ID NO:7 (or itscomplement) under stringent washing conditions, in which the washstringency is equivalent to 0.5×-2×SSC with 0.1% SDS at 55-65° C.,including 0.5×SSC with 0.1% SDS at 55° C., or 2×SSC with 0.1% SDS at 65°C. One of skill in the art can readily devise equivalent conditions, forexample, by substituting SSPE for SSC in the wash solution.

Typical highly stringent washing conditions include washing in asolution of 0.1×-0.2×SSC with 0.1% sodium dodecyl sulfate (SDS) at50-65° C. In other words, nucleic acid molecules encoding a variantIL-31RA polypeptide hybridize with a nucleic acid molecule having thenucleotide sequence of SEQ ID NO:1 (or its complement) under highlystringent washing conditions, in which the wash stringency is equivalentto 0.1×-0.2×SSC with 0.1% SDS at 50-65° C., including 0.1×SSC with 0.1%SDS at 50° C., or 0.2×SSC with 0.1% SDS at 65° C.

The present invention also provides isolated IL-31RA polypeptides thathave a substantially similar sequence identity to the polypeptideshaving amino acid residues 20-519 of SEQ ID NO:6 and/or amino acidresidues 33-532 of SEQ ID NO:8, or their orthologs. The term“substantially similar sequence identity” is used herein to denotepolypeptides comprising at least 70%, at least 80%, at least 90%, atleast 95%, at least 96%, at least 97%, at least 98%, at least 99%, atleast 99-0.5%, or greater than 99.5% sequence identity to the sequencesshown in amino acid residues 20-519 of SEQ ID NO:6 and/or amino acidresidues 33-532 of SEQ ID NO:8, or their orthologs. The presentinvention further includes nucleic acid molecules that encode suchpolypeptides. Methods for determining percent identity are described PCTpublications WO 02/00721 (incorporated by reference) and 04/003140(incorporated by reference).

The present invention provides a method of treating a patient sufferingfrom a skin disorder, the method comprises administering atherapeutically effective amount of an anti-IL-31RA antibody or fragmentto the patient, wherein the anti-IL-31RA antibody or fragment binds withan amino acid sequence having at least 90%, at least 91%, at least 92%,at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, atleast 98%, at least 99%, at least 99.5%, or great than 99.5% sequenceidentity with amino acid residues 20-519 of SEQ ID NO:6 or portionthereof, or amino acid residues 33-532 of SEQ ID NO:8 or portionthereof, and wherein the anti-IL-31RA antibody or fragment prevents,inhibits the progression of, delays the onset of, reduces the severityof, and/or inhibits at least one of the conditions or symptoms of theskin disorder selected from the group consisting of Atopic Dermititis,Contact dermatitis, Drug induced delayed type cutaneous allergicreactions, Toxic epidermal necrolysis, Cutaneous T cell Lymphoma,Bullous pemphigoid, Alopecia aereata, Vitiligo, Acne Rosacea, Prurigonodularis, Scleroderma, and Herpes simplex virus. The anti-IL-31RAantibody may optionally be a polyclonal antibody or a neutralizingmonoclonal antibody (the present invention also provides for a hybridomafor producing the neutralizing IL-31RA monoclonal antibody). Theanti-IL-31RA antibody fragment may optionally be a Fab fragment, a Fab′fragment, a F(ab′)2 fragment, single chain Fv (scFV), dual specificantibody, domain antibody, or bispecific antibody. The anti-IL-31RAantibody or fragment may bind with amino acid residues 20-277 of SEQ IDNO:6 or 33-240 of SEQ ID NO:8. The anti-IL-31RA antibody or fragment maybind with about 4-10 amino acid residues of amino acid residues 20-519of SEQ ID NO:6 or amino acid residues 33-532 of SEQ ID NO:8. Theanti-IL-31RA antibody or fragment may bind with about 10-14 amino acidresidues of amino acid residues 20-519 of SEQ ID NO:6 or amino acidresidues 33-532 of SEQ ID NO:8. The anti-IL-31RA antibody or fragmentmay bind with about 14-30 amino acid residues of amino acid residues20-519 of SEQ ID NO:6 or amino acid residues 33-532 of SEQ ID NO:8. Theanti-IL-31 antibody or fragment may be further conjugated to apolyethylene glycol or to human serum albumin.

The present invention also provides for a method of treating a patientsuffering from a skin disorder, the method comprises administering atherapeutically effective amount of a soluble IL-31RA receptor to thepatient, wherein the soluble IL-31RA receptor has at least 90%, at least91%, at least 92%, at least 93%, at least 94%, at least 95%, at least96%, at least 97%, at least 98%, at least 99%, at least 99.5%, or greatthan 99.5% sequence identity with amino acid residues 20-519 of SEQ IDNO:6 or portion thereof, or amino acid residues 33-532 of SEQ ID NO:8,and wherein the soluble IL-31RA receptor binds with an IL-31 polypeptideconsisting of amino acid residues 1-164 SEQ ID NO:2, and wherein thesoluble IL-31RA receptor prevents, inhibits the progression of, delaysthe onset of, reduces the severity of, and/or inhibits at least one ofthe conditions or symptoms of the skin disorder selected from the groupconsisting of Atopic Dermititis, Contact dermatitis, Drug induceddelayed type cutaneous allergic reactions, Toxic epidermal necrolysis,Cutaneous T cell Lymphoma, Bullous pemphigoid, Alopecia aereata,Vitiligo, Acne Rosacea, Prurigo nodularis, Scleroderma, and Herpessimplex virus. The soluble IL-31RA receptor may comprise amino acidresidues 20-519 of SEQ ID NO:6 or 33-240 of SEQ ID NO:8, amino acidresidues 1-324 of SEQ ID NO:10, or amino acid residues 1-239 of SEQ IDNO:12. The soluble IL-31RA receptor may be further conjugated to the Fcregion of the various immunoglobulins (IgG, IgA, IgD, IgM or IgE).Optionally, the soluble IL-31RA receptor may be an IL-31RA homodimer oran IL-31RA/OSMRbeta heterodimer. The soluble IL-31RA receptor may bindwith an IL-31 polypeptide comprising, consisting essentially of,consisting of amino acid residues 24-164 of SEQ ID NO:2 or 27-164 of SEQID NO:2. The soluble IL-31RA receptor may be further conjugated to apolyethylene glycol or to human serum albumin.

A variety of assays known to those skilled in the art can be utilized todetect antibodies which bind to IL-31RA proteins or polypeptides.Exemplary assays are described in detail in Antibodies: A LaboratoryManual, Harlow and Lane (Eds.), Cold Spring Harbor Laboratory Press,1988. Representative examples of such assays include: concurrentimmunoelectrophoresis, radioimmunoassay, radioimmuno-precipitation,enzyme-linked immunosorbent assay (ELISA), dot blot or Western blotassay, inhibition or competition assay, and sandwich assay. In addition,antibodies can be screened for binding to wild-type versus mutantIL-31RA protein or polypeptide.

Antibodies to IL-31RA may be used for tagging cells that expressIL-31RA; for isolating IL-31RA by affinity purification; for diagnosticassays for determining circulating levels of IL-31RA polypeptides; fordetecting or quantitating soluble IL-31RA as a marker of underlyingpathology or disease; in analytical methods employing FACS; forscreening expression libraries; for generating anti-idiotypicantibodies; and as neutralizing antibodies or as antagonists to blockIL-31 activity in vitro and in vivo. Suitable direct tags or labelsinclude radionuclides, enzymes, substrates, cofactors, inhibitors,fluorescent markers, chemiluminescent markers, magnetic particles andthe like; indirect tags or labels may feature use of biotin-avidin orother complement/anti-complement pairs as intermediates. Antibodiesherein may also be directly or indirectly conjugated to drugs, toxins,radionuclides and the like, and these conjugates used for in vivodiagnostic or therapeutic applications. In addition, antibodies toIL-31RA or fragments thereof may be used in vitro to detect denaturedIL-31RA or fragments thereof in assays, for example, Western Blots orother assays known in the art.

Suitable detectable molecules may be directly or indirectly attached tothe polypeptide or antibody, and include radionuclides, enzymes,substrates, cofactors, inhibitors, fluorescent markers, chemiluminescentmarkers, magnetic particles and the like. Suitable cytotoxic moleculesmay be directly or indirectly attached to the polypeptide or antibody,and include bacterial or plant toxins (for instance, diphtheria, toxin,saporin, Pseudomonas exotoxin, ricin, abrin and the like), as well astherapeutic radionuclides, such as iodine-131, rhenium-188 or yttrium-90(either directly attached to the polypeptide or antibody, or indirectlyattached through means of a chelating moiety, for instance).Polypeptides or antibodies may also be conjugated to cytotoxic drugs,such as adriamycin. For indirect attachment of a detectable or cytotoxicmolecule, the detectable or cytotoxic molecule can be conjugated with amember of a complementary/anticomplementary pair, where the other memberis bound to the polypeptide or antibody portion. For these purposes,biotin/streptavidin is an exemplary complementary/anticomplementarypair.

Polypeptide-toxin fusion proteins or antibody-toxin fusion proteins canbe used for targeted cell or tissue inhibition or ablation (forinstance, to treat cancer cells or tissues). Alternatively, if thepolypeptide has multiple functional domains (i.e., an activation domainor a receptor binding domain, plus a targeting domain), a fusion proteinincluding only the targeting domain may be suitable for directing adetectable molecule, a cytotoxic molecule or a complementary molecule toa cell or tissue type of interest. In instances where the domain onlyfusion protein includes a complementary molecule, the anti-complementarymolecule can be conjugated to a detectable or cytotoxic molecule. Suchdomain-complementary molecule fusion proteins thus represent a generictargeting carrier or vehicle for cell/tissue-specific delivery ofgeneric anti-complementary-detectable/cytotoxic molecule conjugates.

Both skin-homing T cells and epidermal keratinocytes have beenimplicated in the pathology of skin diseases in humans. As shown inExample 1 herein, of the T cell subsets, IL-31 mRNA and proteinexpression is restricted to the skin-homing CLA+ T cell population inhumans. As such, an antagonist to IL-31RA, including an antibody orfragment thereof or soluble receptor (IL-31RA and IL-31RA/OSMRbetasoluble receptors) antagonist will be useful in treating, ablating,inhibiting the progression of, and/or reducing the severity of skin andepidermal diseases which have expression of CLA+ T cells. Such diseasesinclude, for example, atopic dermatitis, contact dermatitis, psoriasis,drug-induced allergic reactions, skin-tropic viruses and viralassociated pruritis, vitiligo, cutaneous T cell lymphoma, alopeciaaerata, acne rosacea, acne vulgaris, prurigo nodularis, and bullouspemphigoid.

Atopic Dermatitis

Atopic dermatitis (AD) is a chronically relapsing inflammatory skindisease with a dramatically increasing incidence over the last decades.Clinically AD is characterized by highly pruritic often excoriatedplaques and papules that show a chronic relapsing course. The diagnosisof AD is mostly based on major and minor clinical findings. See HanifinJ. M., Arch Dermatol: 135, 1551 (1999). Histopathology revealsspongiosis, hyper and focal parakeratosis in acute lesions, whereasmarked epidermal hyperplasia with hyper and parakeratosis,acanthosis/hypergranulosis and perivascular infiltration of the dermiswith lymphocytes and abundant mast cells are the hallmarks of chroniclesions.

T cells play a central role in the initiation of local immune responsesin tissues and evidence suggests that skin-infiltrating T cells inparticular, may play a key role in the initiation and maintenance ofdisregulated immune responses in the skin. Approximately 90% ofinfiltrating T cells in cutaneous inflammatory sites express thecutaneous lymphocyte-associated Ag (CLA+) which binds E-selectin, aninducible adhesion molecule on endothelium (reviewed in Santamaria-BabiL. F., et al., Eur J Dermatol: 14, 13, (2004)). A significant increasein circulating CLA+ T cells among AD patients compared with controlindividuals has been documented (See Teraki Y., et al., Br J Dermatol:143, 373 (2000)), while others have demonstrated that memory CLA+ Tcells from AD patients preferentially respond to allergen extractcompared to the CLA− population (See Santamaria-Babi, L. F., et al., JExp Med:181, 1935, (1995)). In humans, the pathogenesis of atopicdisorders of the skin have been associated with increases in CLA+ Tcells that express increased levels of Th-2-type cytokines like IL-5 andIL-13. See Akdis M., et al., Eur J Immunol: 30, 3533 (2000); and HamidQ., et al., J Allergy Clin Immunol: 98, 225 (1996).

NC/Nga Mice spontaneously develop AD-like lesions that parallel human ADin many aspects, including clinical course and signs, histopathology andimmunopathology when housed in non-specified pathogen-free (non-SPF)conditions at around 6-8 weeks of age. In contrast, NC/Nga mice keptunder SPF conditions do not develop skin lesions. However, onset ofspontaneous skin lesions and scratching behaviour can be synchronized inNC/Nga mice housed in a SPF facility by weekly intradermal injection ofcrude dust mite antigen. See Matsuoka H., et al., Allergy: 58, 139(2003). Therefore, the development of AD in NC/Nga is a useful model forthe evaluation of novel therapeutics for the treatment of AD.

In addition to the NC/Nga model of spontaneous AD, epicutaneoussensitization of mice using OVA can also be used as a model to induceantigen-dependent epidermal and dermal thickening with a mononuclearinfiltrate in skin of sensitized mice. This usually coincides withelevated serum levels of total and specific IgE, however no skin barrierdysfunction or pruritus normally occurs in this model. See Spergel J.M., et al., J Clin Invest, 101: 1614, (1998). This protocol can bemodified in order to induce skin barrier disregulation and pruritis bysensitizing DO11.10 OVA TCR transgenic mice with OVA. Increasing thenumber of antigen-specific T cells that could recognize the sensitizingantigen may increase the level of inflammation in the skin to inducevisible scratching behaviour and lichenification/scaling of the skin.

Both the NC/Nga spontaneous AD model and the OVA epicutaneous DO11.10model are used to investigate expression of IL-31 and IL-31RA in AD. SeeExample 3.

An IL-31RA neutralizing antagonist could be effective in inhibiting,reducing, minimizing or preventing atopic dermatitis reactions. SeeExample 3 for an in vivo model for testing the effect of an IL-31antagonist in an atopic dermatitis model.

Contact Dermatitis

Allergic contact dermatitis is defined as a T cell mediated immunereaction to an antigen that comes into contact with the skin. The CLA+ Tcell population is considered to be involved in the initiation ofdermatitis since allergen dependent T cell responses are largelyconfined to the CLA+ population of cells (See Santamaria-Babi, L. F., etal., J Exp Med:181, 1935, (1995)). Recent data has found that onlymemory (CD45RO+) CD4+ CLA+ and not CD8+ T cells proliferate and produceboth type-1 (IFN-γ) and type-2 (IL-5) cytokines in response to nickel, acommon contact hypersensitivity allergen. Furthermore, cells expressingCLA in combination with CD4, CD45RO (memory) or CD69 are increased afternickel-specific stimulation and express the chemokine receptors CXCR3,CCR4, CCR10 but not CCR6. See Moed H., et al., Br J Dermatol:51, 32,(2004).

In animal models, it has been demonstrated that allergic contactdermatitis is T-cell dependent and that the allergic-responsive T cellsmigrate to the site of allergen application. See generally: Engeman T.M., et al., J Immunol: 164, 5207, (2000); Ferguson T. A. & Kupper T. S.J Immunol: 150, 1172, (1993); and Gorbachev A. V. & Fairchild R. L.Crit. Rev Immunol: 21, 451 (2001). Since CLA+ T cells produce IL-31 andIL-31 stimulation of skin keratinocytes can induce pro-inflammatorychemokines, IL-31 may be involved in the pathophysiology of contactdermatitis.

An IL-31RA neutralizing antagonist, e.g., antibody or fragment thereofor soluble receptor (IL-31RA and IL-31RA/OSMRbeta soluble receptors),could be effective in inhibiting, reducing, minimizing or preventingcontact dermatitis reactions. See Example 2 for an in vivo model fortesting the effect of an IL-31 antagonist in a contact dermatitis model.

Drug-Induced Delayed Type Cutaneous Allergic Reactions

Drug-induced delayed type cutaneous allergic reactions are veryheterogeneous and may mirror many distinct pathophysiological events.See Brockow K., et al., Allergy, 57, 45 (2002). Immunological mechanismsinvolved in these reactions have been shown as either antibody or cellmediated. In immediate drug allergy an IgE-mediated antibody reactioncan be demonstrated by a positive skin prick and/or intradermal testafter 20 min, whereas non-immediate reactions to drugs can occur morethan one hour after last drug intake and are often T-cell mediated.Non-immediate T-cell mediated delayed type reactions can occur inpatients with adverse drug reactions to penicillins for example.Proliferative T cell responses to penicillins have been shown to berestricted to the memory (CD45RO+) CLA+ subpopulation of T cells frompenicillin allergic patients whereas the CD45RO+ CLA− subset shows noproliferative response. See Blanca M., Leyva L., et al., Blood Cells MolDis:31, 75 (2003). Delayed-type hypersensitivity (DTH) reactions can beartificially reproduced in mice, allowing assessment of factors that maybe involved in the initiation and perpetuation of the DTH response. AnIL-31RA neutralizing antagonist, e.g., antibody or soluble receptor(IL-31RA and IL-31RA/OSMRbeta soluble receptors), could be effective ininhibiting, reducing, minimizing or preventing delayed typehypersensitivity reactions. See Example 4 for an in vivo model oftesting the effect of an IL-31 antagonist in a DTH model.

Toxic epidermal necrolysis (TEN) is a very rare but extremely severedrug reaction characterized by widespread apoptosis of epidermis withextensive blisters. Studies have shown that lymphocytes infiltrating theblister are CLA+ T cells and can exhibit cytotoxicity towards epidermalkeratinocytes. See Leyva L., et al., J Allergy Clin Immunol: 105, 157(2000); and Nassif A., Bensussan A., et al., J Allergy Clin Immunol:114,1209 2004). A transgenic mouse system, whereby OVA is expressed underthe control of the keratin-5 (K5) promoter in the epidermal and hairfollicular keratinocytes of mice, has been generated to establish ananimal model for TEN. OVA specific CD8+ T cells, when adoptivelytransferred into K5-OVA mice, undergo activation and proliferation inthe skin-draining lymph nodes and target the skin of K5-OVA mice,resulting in development of skin lesions that are reminiscent of TEN.See Azukizawa H., et al., Eur J Immunol: 33, 1879 (2003). An IL-31RAneutralizing antagonist, e.g., antibody or soluble receptor (IL-31RA andIL-31RA/OSMRbeta soluble receptors), could be effective in inhibiting,reducing, minimizing or preventing TEN reactions.

Bullous Pemphigoid

Bullous pemphigoid is a subepidermal disorder which manifests assubepidermal blisters with a dermal infiltrate of neutrophils andeosinophils. Diagnosis is characterized by the presence ofantigen-specific antibodies against specific adhesion proteins of theepidermis and dermal-epidermal junction. See Jordon R. E., et al., JAMA:200, 751 (1967). Studies analyzing the role of T cells in thepathogenesis of bullous pemphigoid by analysis of PBL and skin blister Tcells have found a predominance of CLA+ T cells expressing increasedlevels of Th2-cytokines like IL-4 and IL-13. See Teraki Y., et al., JInvest Dermatol: 117, 1097 (2001). In bullous pemphigoid patientsfollowing therapy with systemic corticosteroids, the frequency of CLA+,but not CLA−, interleukin-13-producing cells is significantly decreased.Decreases in CLA+ cells following corticosteroid treatment is associatedwith clinical improvement. See Teraki, ibid. Neutralization of IL-31 byan IL-31RA antagonist, e.g., antibody or fragment thereof or solublereceptor (IL-31RA and IL-31RA/OSMRbeta soluble receptors), may improveclinical outcome of bullous pemohigoid.

Alopecia Areata

Alopecia areata (AA) is regarded as a tissue-restricted autoimmunedisease of hair follicles in which follicular activity is arrestedbecause of the continued activity of lymphocytic infiltrates. AA resultsin patches of complete hair loss anywhere on the body, though actualloss of hair follicles does not occur, even in hairless lesions.Although clinical signs of inflammation are absent, skin biopsies fromsites of active disease show perifollicular lymphocytic inflammation ofprimarily CD4+ cells, along with a CD8+ intrafollicular infiltrate. SeeKalish R. S. & Gilhar A. J Investig Dermatol Symp Proc: 8, 164 (2003).

Studies have shown that scalp skin infiltrating CD4+ or CD8+ lymphocytesexpress CLA and, in peripheral blood of individuals with AA, the percentof CLA+ CD4+ or CD8+ lymphocytes is significantly higher than that ofnormal controls. Furthermore, patients with severe or progressive AAshow a much higher CLA-positivity compared to patients recovering fromthe disease and a decrease in percent CLA+ cells parallels a goodclinical course. See Yano S., et al., Acta Derm Venereol: 82, 82 (2002).These studies therefore suggest that CLA+ lymphocytes may play animportant role in AA. Xenograft models have demonstrated that activatedT cells are likely to play a role in the pathogenesis of AA. Lesionalscalp from AA patients grafted onto nude mice regrows hair coincidentwith a loss of infiltrating lymphocytes from the graft and, transfer ofactivated lesional T cells to SCID mice can transfer hair loss to humanscalp explants on SCID mice. See Kalish R. S. & Gilhar A. J InvestigDermatol Symp Proc: 8, 164 (2003).

A variety of immunomodulating therapies are part of the usual treatmentfor this disorder however none of these treatments have been consistentin their efficacy. See Tang L., et al., J Invest Dermatol: 120, 400(2003); Tang L., et al., (2004); and Tang L., et al., J Am AcadDermatol: 49, 1013 (2003). Neutralizing anti-IL-31RA antibody orfragment thereof or IL-31RA soluble receptor (IL-31RA andIL-31RA/OSMRbeta soluble receptors) may be effective to limit, reduce,inhibit, or prevent the effects of the development of AA.

Acne Vulgaris/Acne Rosacea

Acne vulgaris, a disorder of the pilosebaceous apparatus, is the mostcommon skin problem of adolescence. Abnormalities in follicularkeratinization are thought to produce the acne lesion. Acne rosacea isdifferentiated from acne vulagaris by the presence of red papules,pustules, cysts and extensive telangiectasias, but the absence ofcomedones (white heads). Increased sebum excretion from sebaceous glandsis a major factor in the pathophysiology of acne vulgaris. Othersebaceous gland functions are also associated with the development ofacne, including sebaceous proinflammatory lipids; different cytokinesproduced locally; periglandular peptides and neuropeptides, such ascorticotrophin-releasing hormone, which is produced by sebocytes; andsubstance P, which is expressed in the nerve endings at the vicinity ofhealthy-looking glands of acne patients. See Zouboulis C. C. ClinDermatol: 22, 360 (2004).

Although the pathophysiology of acne vulgaris and acne rosacea remainsunknown, clinical observations and histopathologic studies suggest thatinflammation of the pilosebaceous follicle may be central to thepathogenesis of rosacea and acne vulgaris. Early studies on analysis ofT cell subsets infiltrating rosacea legions indicated that the majorityof T cells expressed CD4. See Rufli T. & Buchner S. A. Dermatologica:169, 1 (1984).

CD4+ T cells produce IL-31 and IHC analysis of skin for IL-31 expressionsuggests that IL-31 is expressed in sebaceous and sweat glands. IL-31stimulation of epidermal keratinocytes induces expression of chemokineswhich likely results in cellular infiltration suggesting that IL-31 maycontribute to the pro-inflammatory response in skin. IL-31 may thereforecontribute to the pathophysiology of acne rosacea and acne vulgaris.Accordingly, an IL-31RA antagonist, such as an anti-IL-31RA antibody orfragment thereof, or an IL-31RA soluble receptor (IL-31RA andIL-31RA/OSMRbeta soluble receptors) can be useful to treat, reduce theseverity of, inhibit the progression of, ablate, and/or eliminate one ormore symptoms associated with acne rosacea and acne vulgaris.

Prurigo Nodularis

Prurigo nodularis is an eruption of lichenified or excoriated nodulescaused by intractable pruritus that is difficult to treat. While chronicrubbing results in lichenification, and scratching in linearexcoriations, individuals who pick and gouge at their itchy, irritatedskin tend to produce markedly thickened papules known as prurigonodules. Although prurigo nodularis is not specific to atopicdermatitis, many patients with these nodules also have an atopicreaction, which manifests as allergic rhinitis, asthma, or food allergy.T cells represent the majority of infiltrating cells in prurigo lesionsand these lesions often represents the most pruritic skin lesion inatopy patients.

Topical treatment of prurigo nodularis with capsaicin, an anti-pruriticalkaloid that interferes with the perception of pruritis and pain bydepletion of neuropeptides like substance P in small sensory cutaneousnerves, has proven to be an effective and safe regimen resulting inclearing of the skin lesions. See Stander S., et al., J Am AcadDermatol: 44, 471 (2001). Studies of the itch response in NC/Nga miceusing capsaicin treatment showed that the spontaneous development ofdermatitis lesions was almost completely prevented. Furthermore, theelevation of serum IgE levels was significantly suppressed andinfiltrating eosinophils and mast cell numbers in lesional skin ofcapsaicin treated mice were reduced. See Mihara K., et al., Br JDermatol: 151, 335 (2004). The observations from this group suggest thatscratching behaviour might contribute to the development of dermatitisby enhancing various immunological responses, therefore implying thatprevention of the itch sensation and/or itch-associated scratchingbehaviour might be an effective treatment for AD. See Mihara K., et al.,Br J Dermatol: 151, 335 (2004).

Chronic delivery of IL-31 induces pruritis and alopecia in mice followedby the development of skin lesions resembling dermatitis suggesting thatIL-31 induces itching. See Dillon S. R., et al., Nat Immunol: 5, 752(2004). The involvement of IL-31 was tested in induction of the itchresponse by two methods (i) capsaicin treatment of IL-31-treated miceand (ii) IL-31 treatment of Tac1 knockout mice, which have significantlyreduced nociceptive pain responses because of lack of expression ofneuropeptides in Example 5. In addition, whether neutralization of IL-31in IL-31 treated mice could prevent pruritis and alopecia was tested inExample 5.

Skin-Tropic Viruses and Viral Associated Pruritis

Herpes Simplex Virus (HSV)-specific CD8+ T cells in the peripheral bloodand HSV-specific CD8+ T cells recovered from herpes lesions express highlevels of CLA where as non-skin-tropic herpes virus-specific CD8+ Tcells lack CLA expression. See Koelle D. M., et al., J Clin Invest: 110,537 (2002). HSV-2 reactive CD4+ T lymphocytes also express CLA, but atlevels lower than those previously observed for CD8+ T lymphocytes. SeeGonzalez J. C., et al., J Infect Dis: 191, 243 (2005). Pruritis has alsobeen associated with herpes viral infections (See Hung K. Y., et al.,Blood Purif: 16, 147 (1998), though other viral diseases, like HIV, havealso been associated with pruritic skin lesions. Severe, intractablepruritus, often associated with erythematopapular skin lesions andhypereosinophilia, is a condition observed in some nonatopic,HIV-infected patients 36. See Singh F. & Rudikoff D, Am J Clin Dermatol;4, 177 (2003); and Milazzo F., Piconi S., et al., Allergy: 54, 266(1999).

The association of skin-tropic viruses with pruritis and CLA+ T cellssuggests that IL-31 producing T cells may be involved in thepathophysiology of viral infections.

Inflammation is a protective response by an organism to fend off aninvading agent. Inflammation is a cascading event that involves manycellular and humoral mediators. On one hand, suppression of inflammatoryresponses can leave a host immunocompromised; however, if leftunchecked, inflammation can lead to serious complications includingchronic inflammatory diseases (e.g., rheumatoid arthritis, multiplesclerosis, inflammatory bowel disease and the like), septic shock andmultiple organ failure. Importantly, these diverse disease states sharecommon inflammatory mediators. The collective diseases that arecharacterized by inflammation have a large impact on human morbidity andmortality. Therefore it is clear that anti-inflammatory molecules, suchas anti-IL-31RA antibodies and fragments thereof, and IL-31RA solublereceptors as described herein, could have crucial therapeutic potentialfor a vast number of human and animal diseases, from asthma and allergyto autoimmunity and septic shock. As such, use of anti-inflammatoryanti-IL-31RA antibodies and fragments thereof, and IL-31RA solublereceptors as described herein can be used therapeutically as IL-31RAantagonists for treating, reducing the severity of, inhibiting theprogression of, and ablating diseases such as arthritis, endotoxemia,inflammatory bowel disease, psoriasis, related disease and the like.

IL-31 has been shown to induce several chemokine and cytokine genes innormal human epidermal keratinocytes (NHEKs), including genes encodingGROα, (CXCL1), TARC (CC117), MIP3β, (CCL19), MDC (CCL22), MIP-3 (CCL23),MIP-1 β (CCL4), and I-309. See Dillon S. R., et al., Nat Immunol: 5, 752(2004). TARC and MDC bind CCR4, a chemokine receptor associated withTh2-type T cells and predominantly expressed by CLA+ T cells inperipheral blood. Both chemokines have been implicated in therecruitment of T cells into the skin of AD patients suggesting thatthese chemokines contribute to the inflammatory process associated withthe pathogenesis of AD. See Example 10 for a model to measure thereduction in TARC and MDC levels by administering an IL-31 antagonist.

Psoriasis is a chronic skin condition that affects more than sevenmillion Americans. Psoriasis occurs when new skin cells grow abnormally,resulting in inflamed, swollen, and scaly patches of skin where the oldskin has not shed quickly enough. Plaque psoriasis, the most commonform, is characterized by inflamed patches of skin (“lesions”) toppedwith silvery white scales. Psoriasis may be limited to a few plaques orinvolve moderate to extensive areas of skin, appearing most commonly onthe scalp, knees, elbows and trunk. Although it is highly visible,psoriasis is not a contagious disease. The pathogenesis of the diseasesinvolves chronic inflammation of the affected tissues. Anti-IL-31RAantibodies and fragment thereof and soluble receptors (IL-31RA andIL-31RA/OSMRbeta soluble receptors) could serve as a valuabletherapeutic to treat, inhibit the progression of, reduce the severityof, reduce inflammation and pathological effects in psoriasis, otherinflammatory skin diseases, skin and mucosal allergies, and relateddiseases.

Psoriasis is a T-cell mediated inflammatory disorder of the skin thatcan cause considerable discomfort. It is a disease for which there is nocure and affects people of all ages. Psoriasis affects approximately twopercent of the populations of European and North America. Althoughindividuals with mild psoriasis can often control their disease withtopical agents, more than one million patients worldwide requireultraviolet or systemic immunosuppressive therapy. Unfortunately, theinconvenience and risks of ultraviolet radiation and the toxicities ofmany therapies limit their long-term use. Moreover, patients usuallyhave recurrence of psoriasis, and in some cases rebound, shortly afterstopping immunosuppressive therapy.

The present invention provides a method for inhibiting activation ordifferentiation of monocytes/macrophages. Monocytes are incompletelydifferentiated cells that migrate to various tissues where they matureand become macrophages. Macrophages play a central role in the immuneresponse by presenting antigen to lymphocytes and play a supportive roleas accessory cells to lymphocytes by secreting numerous cytokines.Macrophages can internalize extracellular molecules and upon activationhave an increased ability to kill intracellular microorganisms and tumorcells. Activated macrophages are also involved in stimulating acute orlocal inflammation.

The molecules of the present invention have particular use in themonocyte/macrophage arm of the immune system. Methods are known that canassess such activity. For example, interferon gamma (IFN-γ) is a potentactivator of mononuclear phagocytes. For example, an increase inexpression of IL-31RA upon activation of THP-1 cells (ATCC No. TIB-202)with interferon gamma could suggest that this receptor is involved inmonocyte activation. Monocytes are incompletely differentiated cellsthat migrate to various tissues where they mature and becomemacrophages. Macrophages play a central role in the immune response bypresenting antigen to lymphocytes and play a supportive role asaccessory cells to lymphocytes by secreting numerous cytokines.Macrophages can internalize extracellular molecules and upon activationhave an increased ability to kill intracellular microorganisms and tumorcells. Activated macrophages are also involved in stimulating acute orlocal inflammation. Moreover, monocyte-macrophage function has beenshown to be abnormal in a variety of diseased states. For example see,Johnston, R B, New Eng. J. Med. 318:747-752, 1998.

One of skill in the art would recognize that agonists of IL-31RAreceptor, such as agonist IL-31RA antibody, are useful. For example,depressed migration of monocytes has been reported in populations with apredisposition to infection, such as newborn infants, patients receivingcorticosteroid or other immunosuppressive therapy, and patients withdiabetes mellitus, burns, or AIDS. Agonists for IL-31RA, such as agonistIL-31RA antibody, could result in an increase in the ability ofmonocytes to migrate and possibly prevent infection in thesepopulations. There is also a profound defect of phagocytic killing bymononuclear phagocytes from patients with chronic granulomatous disease.This results in the formation of subcutaneous abscesses, as well asabscesses in the liver, lungs, spleen, and lymph nodes. An agonist ofIL-31RA receptor such as agonist IL-31RA antibody, could correct orimprove this phagocytic defect. In addition, defective monocytecytotoxicity has been reported in patients with cancer andWiskott-Aldrich syndrome (eczema, thrombocytopenia, and recurrentinfections). Activation of monocytes by agonists of IL-31RA receptor,such as agonist IL-31RA antibody, could aid in treatment of theseconditions. The monocyte-macrophage system is prominently involved inseveral lipid-storage diseases (sphingolipidoses) such as Gaucher'sdisease. Resistance to infection can be impaired because of a defect inmacrophage function, which could be treated by agonists to IL-31RAreceptor such as agonist IL-31RA antibody.

Using methods known in the art, and disclosed herein, one of skill couldreadily assess the activity of IL-31RA agonists and antagonists indiseases that have a high correlation of CLA+ T cells. In addition, asIL-31 is expressed in a T-cell, macrophage and monocyte-specific manner,and these diseases involve abnormalities in monocytic cells, such ascell proliferation, function, localization, and activation, thepolynucleotides, polypeptides, and antibodies of the present inventioncan be used to as diagnostics to detect such monocytic cellabnormalities, and indicate the presence of disease. Such methodsinvolve taking a biological sample from a patient, such as blood,saliva, or biopsy, and comparing it to a normal control sample.Histological, cytological, flow cytometric, biochemical and othermethods can be used to determine the relative levels or localization ofIL-31, or cells expressing IL-31, i.e., monocytes, in the patient samplecompared to the normal control. A change in the level (increase ordecrease) of IL-31 expression, or a change in number or localization ofmonocytes (e.g., increase or infiltration of monocytic cells in tissueswhere they are not normally present) compared to a control would beindicative of disease. Such diagnostic methods can also includemeasuring TARC and MDC, for example. Such methods are well known in theart and disclosed herein.

IL-31RA antagonists, such as anti-IL-31RA antibodies, can be used tomodulate the immune system by binding IL-31RA receptor, and thus,preventing the binding of IL-31 with endogenous IL-31 receptor.Alternatively, IL-31RA antagonists, such as soluble IL-31RA andIL-31RA/OSMRbeta receptors, can also be used to modulate the immunesystem by inhibiting the binding of IL-31 with the endogenous IL-31RAreceptor. Accordingly, the present invention includes the use of IL-31RAantibodies and fragments thereof as well as IL-31RA soluble receptors(IL-31RAa do IL-31RA/OSMRbeta) which can be administered to a subjectwhich has excess IL-31. IL-31RA antagonists (e.g., anti-IL-31RAantibodies and fragments thereof and soluble IL-31RA and solubleIL-31RA/OSMRbeta receptors) can be also used to treat diseases that havea high correlation of CLA+ T cells. Suitable subjects include mammals,such as humans.

IL-31 has been shown to be expressed in activated mononuclear cells, andmay be involved in regulating inflammation. As such, antibodies andsoluble receptors of the present invention can be assayed and used fortheir ability to modify inflammation, or can be used as a marker forinflammation. Methods to determine proinflammatory and anti-inflammatoryqualities of IL-31 are known in the art and discussed herein. Moreover,it may be involved in up-regulating the production of acute phasereactants, such as serum amyloid A (SAA), α1-antichymotrypsin, andhaptoglobin, and that expression of IL-31RA receptor may be increasedupon injection of lipopolysaccharide (LPS) in vivo that are involved ininflammatory response (Dumoutier, L. et al., Proc. Nat'l. Acad. Sci.97:10144-10149, 2000). Production of acute phase proteins, such as SAA,is considered a short-term survival mechanism where inflammation isbeneficial; however, maintenance of acute phase proteins for longerperiods contributes to chronic inflammation and can be harmful to humanhealth. For review, see Uhlar, C M and Whitehead, A S, Eur. J. Biochem.265:501-523, 1999, and Baumann H. and Gauldie, J. Immunology Today15:74-80, 1994. Moreover, the acute phase protein SAA is implicated inthe pathogenesis of several chronic inflammatory diseases, is implicatedin atherosclerosis and rheumatoid arthritis, and is the precursor to theamyloid A protein deposited in amyloidosis (Uhlar, C M and Whitehead,supra.). Thus, where a ligand such as IL-31 that acts as apro-inflammatory molecule and induces production of SAA, antagonistswould be useful in treating inflammatory disease and other diseasesassociated with acute phase response proteins induced by the ligand.Such antagonists are provided by the present invention. For example, amethod of reducing inflammation comprises administering to a mammal withinflammation a therapeutically effective amount of a compositioncomprising anti-IL-31RA antibody (e.g., neutralizing antibody) orfragment thereof, or a soluble receptor (e.g., IL-31RA andIL-31RA/OSMRbeta soluble receptors) that is sufficient to reduceinflammation. Moreover, a method of suppressing an inflammatory responsein a mammal with inflammation can comprise: (1) determining a level ofserum amyloid A protein; (2) administering a composition comprising ananti-IL-31RA antibody as described herein or soluble receptor (IL-31RAand IL-31RA/OSMRbeta soluble receptors) in an acceptable pharmaceuticalcarrier; (3) determining a post administration level of serum amyloid Aprotein; (4) comparing the level of serum amyloid A protein in step (1)to the level of serum amyloid A protein in step (3), wherein a lack ofincrease or a decrease in serum amyloid A protein level is indicative ofsuppressing an inflammatory response.

Moreover, anti-IL-31RA antibodies and fragments thereof that block thebinding and/or signaling of IL-31 to IL-31RA, and soluble IL-31RAreceptors (IL-31RA and IL-31RA/OSMRbeta) that bind IL-31 and thusprevent the binding of IL-31 to cellular-based IL-31RA are useful toantagonize or block signaling of IL-31 and are thus useful in thetreatment of, inhibit the progression of, reduce the severity of, reduceone or more symptoms associated with Contact dermatitis, Drug induceddelayed type cutaneous allergic reactions, Toxic epidermal necrolysis,Cutaneous T cell Lymphoma, Bullous pemphigoid, Alopecia aereata,Vitiligo, Acne Rosacea, Prurigo nodularis, Scleroderma, and Herpessimplex virus.

Anti-IL-31RA antibodies, and soluble IL-31RA (IL-31RA and IL-31RA/OSMRbeta soluble receptors) comprising receptors are useful as antagonists ofIL-31. Such antagonistic effects can be achieved by directneutralization or binding of its natural ligand. In addition toantagonistic uses, the soluble receptors can bind IL-31 and act ascarrier or carrier proteins, in order to transport IL-31 to differenttissues, organs, and cells within the body. As such, the solublereceptors can be fused or coupled to molecules, polypeptides or chemicalmoieties that direct the soluble-receptor-Ligand complex to a specificsite, such as a tissue, specific immune cell, monocytes, or tumor. Forexample, in acute infection or some cancers, benefit may result frominduction of inflammation and local acute phase response proteins. Thus,the soluble receptors described herein or antibodies (and fragmentsthereof) of the present invention can be used to specifically direct theaction of a pro-inflammatory IL-31 ligand. See, Cosman, D. Cytokine 5:95-106, 1993; and Fernandez-Botran, R. Exp. Opin. Invest. Drugs9:497-513, 2000.

IL-31 may also be used within diagnostic systems for the detection ofcirculating levels of ligand, and in the detection of acute phaseinflammatory response. Within a related embodiment, antibodies or otheragents that specifically bind to IL-31, e.g., soluble IL-31RA andsoluble IL-31RA/OSMRbeta, can be used to detect circulating IL-31polypeptides. Elevated or depressed levels of ligand or receptorpolypeptides may be indicative of pathological conditions, includinginflammation or cancer. Moreover, detection of acute phase proteins ormolecules such as IL-31 can be indicative of a chronic inflammatorycondition in certain disease states (e.g., rheumatoid arthritis).Detection of such conditions serves to aid in disease diagnosis as wellas help a physician in choosing proper therapy.

Generally, the dosage of administered IL-31RA antibody or fragmentthereof or soluble IL-31RA receptor or soluble IL-31RA/OSMRbeta receptorwill vary depending upon such factors as the patient's age, weight,height, sex, general medical condition and previous medical history.Typically, it is desirable to provide the recipient with a dosage ofIL-31RA antibody or fragment thereof or soluble IL-31RA receptor orsoluble IL-31RA/OSMRbeta receptor which is in the range of from about 1pg/kg to 10 mg/kg (amount of agent/body weight of patient), although alower or higher dosage also may be administered as circumstancesdictate. One skilled in the art can readily determine such dosages, andadjustments thereto, using methods known in the art.

Administration of IL-31RA antibody or fragment thereof or solubleIL-31RA receptor or soluble IL-31RA/OSMRbeta receptor to a subject canbe topical, intradermal, inhalant, intravenous, intraarterial,intraperitoneal, intramuscular, subcutaneous, intrapleural, intrathecal,by perfusion through a regional catheter, or by direct intralesionalinjection. When administering therapeutic proteins by injection, theadministration may be by continuous infusion or by single or multipleboluses.

Additional routes of administration include oral, mucosal-membrane,pulmonary, and transcutaneous. Oral delivery is suitable for polyestermicrospheres, zein microspheres, proteinoid microspheres,polycyanoacrylate microspheres, and lipid-based systems (see, forexample, DiBase and Morrel, “Oral Delivery of MicroencapsulatedProteins,” in Protein Delivery: Physical Systems, Sanders and Hendren(eds.), pages 255-288 (Plenum Press 1997)). The feasibility of anintranasal delivery is exemplified by such a mode of insulinadministration (see, for example, Hinchcliffe and Illum, Adv. DrugDeliv. Rev. 35:199 (1999)). Dry or liquid particles comprising IL-31RAantibody or fragment thereof or soluble IL-31RA receptor or solubleIL-31RA/OSMRbeta receptor can be prepared and inhaled with the aid ofdry-powder dispersers, liquid aerosol generators, or nebulizers (e.g.,Pettit and Gombotz, TIBTECH 16:343 (1998); Patton et al., Adv. DrugDeliv. Rev. 35:235 (1999)). This approach is illustrated by the AERXdiabetes management system, which is a hand-held electronic inhaler thatdelivers aerosolized insulin into the lungs. Studies have shown thatproteins as large as 48,000 kDa have been delivered across skin attherapeutic concentrations with the aid of low-frequency ultrasound,which illustrates the feasibility of trascutaneous administration(Mitragotri et al., Science 269:850 (1995)). Transdermal delivery usingelectroporation provides another means to administer IL-31RA antibody orfragment thereof or soluble IL-31RA receptor or soluble IL-31RA/OSMRbetareceptor (Potts et al., Pharm. Biotechnol. 10:213 (1997)).

A pharmaceutical composition comprising a IL-31RA antibody or fragmentthereof (antagonist and agonist) or a soluble IL-31RA receptor or asoluble IL-31RA/OSMRbeta receptor can be formulated according to knownmethods to prepare pharmaceutically useful compositions, whereby thetherapeutic proteins are combined in a mixture with a pharmaceuticallyacceptable carrier. A composition is said to be a “pharmaceuticallyacceptable carrier” if its administration can be tolerated by arecipient patient. Sterile phosphate-buffered saline is one example of apharmaceutically acceptable carrier. Other suitable carriers arewell-known to those in the art. See, for example, Gennaro (ed.),Remington's Pharmaceutical Sciences, 19th Edition (Mack PublishingCompany 1995).

For purposes of therapy, an IL-31RA antibody or fragment thereof(antagonist and agonist) or a soluble IL-31RA receptor or a solubleIL-31RA/OSMRbeta receptor and a pharmaceutically acceptable carrier areadministered to a patient in a therapeutically effective amount. Acombination of an IL-31RA antibody (antagonist and agonist) or a solubleIL-31RA receptor (e.g., IL-31RA homodimer and a zcytor17/OSMRbetaheterodimer) and a pharmaceutically acceptable carrier is said to beadministered in a “therapeutically effective amount” if the amountadministered is physiologically significant. An agent is physiologicallysignificant if its presence results in a detectable change in thephysiology of a recipient patient. For example, an agent used to treatinflammation is physiologically significant if its presence alleviatesat least a portion of the inflammatory response.

A pharmaceutical composition comprising an IL-31RA antibody or fragmentthereof (antagonist and agonist) or a soluble IL-31RA receptor or asoluble IL-31RA/OSMRbeta receptor can be furnished in liquid form, in anaerosol, or in solid form. Liquid forms, are illustrated by injectablesolutions, aerosols, droplets, topological solutions and oralsuspensions. Exemplary solid forms include capsules, tablets, andcontrolled-release forms. The latter form is illustrated by miniosmoticpumps and implants (Bremer et al., Pharm. Biotechnol. 10:239 (1997);Ranade, “Implants in Drug Delivery,” in Drug Delivery Systems, Ranadeand Hollinger (eds.), pages 95-123 (CRC Press 1995); Bremer et al.,“Protein Delivery with Infusion Pumps,” in Protein Delivery: PhysicalSystems, Sanders and Hendren (eds.), pages 239-254 (Plenum Press 1997);Yewey et al., “Delivery of Proteins from a Controlled Release InjectableImplant,” in Protein Delivery: Physical Systems, Sanders and Hendren(eds.), pages 93-117 (Plenum Press 1997)). Other solid forms includecreams, pastes, other topological applications, and the like.

An IL-31RA antibody or fragment thereof (antagonist and agonist) or asoluble IL-31RA receptor or a soluble IL-31RA/OSMRbeta receptor can beencapsulated within liposomes using standard techniques of proteinmicroencapsulation (see, for example, Anderson et al., Infect. Immun.31:1099 (1981), Anderson et al., Cancer Res. 50:1853 (1990), and Cohenet al., Biochim. Biophys. Acta 1063:95 (1991), Alving et al.“Preparation and Use of Liposomes in Immunological Studies,” in LiposomeTechnology, 2nd Edition, Vol. III, Gregoriadis (ed.), page 317 (CRCPress 1993), Wassef et al., Meth. Enzymol. 149:124 (1987)). As notedabove, therapeutically useful liposomes may contain a variety ofcomponents. For example, liposomes may comprise lipid derivatives ofpoly(ethylene glycol) (Allen et al., Biochim. Biophys. Acta 1150:9(1993)).

Other dosage forms can be devised by those skilled in the art, as shown,for example, by Ansel and Popovich, Pharmaceutical Dosage Forms and DrugDelivery Systems, 5^(th) Edition (Lea & Febiger 1990), Gennaro (ed.),Remington Pharmaceutical Sciences, 19^(th) Edition (Mack PublishingCompany 1995), and by Ranade and Hollinger, Drug Delivery Systems (CRCPress 1996).

The complete disclosure of all patents, patent applications, andpublications, and electronically available material (e.g., GenBank aminoacid and nucleotide sequence submissions) cited herein are incorporatedby reference. The foregoing detailed description and examples have beengiven for clarity of understanding only. No unnecessary limitations areto be understood therefrom. The invention is not limited to the exactdetails shown and described, for variations obvious to one skilled inthe art will be included within the invention defined by the claims.

EXAMPLES Example 1 Determination of Human Primary T Cell Types thatExpress IL-31 Upon Stimulation

Selection of Study Subjects and Biopsies

Twelve patients with AD (moderate to severe disease; median age was 32years old with skin involvement of 5-45%), 6 patients with psoriasis(median age was 56 years old with skin involvement of 10-65%) and 12healthy individuals (median age 34 years) were included in A study afterinformed consent. None of the patients had received any systemiccorticosteroids previously. All patients were off topicalcorticosteroids for one week before their skin biopsy or blood drawing.Two mm punch biopsies were taken from 1) acute erythematous AD lesionsof less than three days' onset, 2) chronic, lichenified AD lesions ofgreater than two weeks' duration, 3) chronic psoriasis lesions, and 4)normal skin. The skin samples were immediately frozen at −70° C. forimmunohistochemistry or Western and immuno-dot blotting.

Isolation and Activation of Primary Human T Cell Subsets:

To isolate various T cell subsets, human PBMCs from the donors wereisolated using standard Ficoll gradient centrifugation. Total T cellswere then isolated using the T Cell Isolation Kit II (Miltenyi Biotec)according to the manufacturer's instructions. Separation efficiency wasassessed using standard flow cytometry and determined to be >95% Tcells. To separate CD45RA+ “naïve” T cells from the CD45RO+ “memory” Tcells, the total T cell population was incubated with anti-CD45ROmicrobeads (Miltenyi Biotec) for 15 minutes at +4° C. and magneticallyseparated according to the manufacturers instructions. The naïve andmemory T cell populations were determined to be >90% pure by flowcytometry.

CD45RO+ memory T cells are often tissue specific and cutaneouslymphocyte antigen (CLA) is used to differentiate skin-homing T cellsfrom gut-homing T cells expressing α4/β7 on their surface. To determinewhich of these cell types produce IL-31, CLA+ T cells were isolated fromtotal T cells, activated and conditioned media was collected for theIL-31 bioassay. To do this, total T cells were isolated and thenincubated on ice for 20 minutes in 1 mL of a 1:50 dilution ofanti-CLA-FITC antibody (PharMingen). Cells were then washed, resuspendedin MACS buffer and incubated with anti-FITC microbeads (Miltenyi Biotec)for 15 minutes at +4° C. The cells were then washed, resuspended andmagnetically separated over an LS column according to the manufacturer'sinstructions. The labeled T cells were later determined to be >80% purewhile the CLA-depleted T cells were >98% CLA−. Both CLA+ and CLA− Tcells were collected and cultured concurrently.

To activate the CD45RA+ and CD45RO+ T cell subsets, cells were culturedovernight in 24-well tissue culture plates pretreated with 2.0 μg/mLanti-CD3 antibody (Southern Biotechnology). The cells were plated at aconcentration of 2.5×10⁶ cells/mL in tissue culture media (RPMI, 5%fetal bovine serum, L-Glutamine and Sodium Pyruvate (all Gibco))supplemented with 2.0 μg/mL anti-CD28 (Southern Biotechnology) andplaced in a +37° C. incubator. After four hours, half of the wells wereharvested, cells pelleted and conditioned media frozen at −20° C. untiltime of IL-31 bioassay.

The CLA+ and CLA− T cell subsets were activated similarly in 48-welltissue culture plates that were pretreated with 2.0 μg/mL anti-CD3antibody (Southern Biotechnology). The cells were activated for 16 hoursor 24 hours in a +37° C. incubator at a concentration of 6.25×10⁵cells/mL. Samples were harvested, cells pelleted and conditioned mediafrozen at −20° C. until time of IL-31 bioassay. For suboptimalactivation, CLA+ T cells were cultured in plates pre-treated with 0.5ug/ml of anti-CD3 antibody.

Human IL-31 Bioassay Protocol:

BAF3 cells transfected with hIL-31RA, hOSMRbeta, and KZ134 were grown to5×10⁵ and 1×10⁶ cells/mL. Cells were washed with assay media (RPMI 1640,10% FBS, L-Glutamine, Sodium Pyruvate, and Pen/Strep (all Gibco)) andresuspended at 3×10⁵ cell/mL in assay medium. In a 96-well opaque plate,hIL-31 standards were titered in duplicate from 600 pg/mL to 9.38 pg/mLin assay medium via a 100 μL/well, 1:2 serial dilution. Quality controlstandards were added in duplicate to the plate at 350 pg/mL and 35 pg/mLin 100 μL. Test samples were often diluted 1:2 or 1:4 and added induplicate to the sample wells. 100 μL of the washed BAF3 cells were thenadded to each well for a final concentration of 3×10⁴ cells/well. Theplate was then incubated for 16-24 hours at +37° C. in a 5% CO₂incubator. The plate was then centrifuged at 1200 RPM for 5 minutes,media flicked off and 25 μL/well of lysis buffer (Promega) added to eachwell. After 10 minutes the plate was read on a luminometer (Berthold).The luminometer added 40 μL/well of luciferase substrate mix (Promega)and integrated the luminescence for a period of 4 seconds. Luminescencevalues were exported to a spreadsheet where they were analyzed andconverted into picograms of IL-31 per 10⁶ cells per mL of volume. Thedata is summarized in Table 1.

Results of IL-31 Bioassay:

The results from the CD45RA+ and the CD45RO+ T cell samples revealedthat IL-31 was primarily produced by activated CD45RO+ memory T cells.The CD45RA+ and CD45RO+ T cells from both donors produced no detectableIL-31 when unstimulated. However, the CD45RO+ samples from both donors#3 and #4 generated significant levels of IL-31 following a 24 houractivation with plate-bound anti-CD3 and soluble anti-CD28 (110.4 pg/10⁶cells/mL and 145.6 pg/10⁶ cells/mL respectively). Conversely, when theCD45RA+ T cells from donors #3 and #4 were activated with anti-CD3 andanti-CD28, they produced very low amounts of IL-31 (13.1 pg/10⁶ cells/mLand 12.7 pg/10⁶ cells/mL respectively).

The CLA+ and CLA− T cell samples revealed that IL-31 seems to be madealmost entirely by activated CLA+ T cells. The CLA− population of Tcells (which includes naïve T cells, α4/β7 gut-homing memory T cells,and tissue uncommitted T cells) from both donors generated no detectablelevels of IL-31 regardless of time point or activation condition. TheCLA+ T cells on the other hand, generated very high levels of IL-31 whenstimulated with 2.0 μg/mL plate-bound anti-CD3 antibody. Donor #5generated 1385.7 pg/10⁶ cells/mL IL-31 by 16 hours and >1920 pg/10⁶cells/mL by 24 hours. Donor #6 generated 121.3 pg/10⁶ cells/mL IL-31 at16 hours and 328.9 pg/10⁶ cells/mL IL-31 at 24 hours. These resultsclearly demonstrate that of the T cell subsets, IL-31 seems to be madespecifically by cutaneous (CLA+) T cells under standard activationconditions.

TABLE 1 IL-31 Donor# Cell Type Activation IL-31 (pg/10⁶ cells/mL)(pg/10⁶ cells/mL)  6 hr 24 hr 3 CD45RA+ αCD3+αCD28 Below Detection 13.13 CD45RO+ αCD3+αCD28 8.6 110.4 4 CD45RA+ αCD3+αCD28 6.7 12.7 4 CD45RO+αCD3+αCD28 11.9 145.6 16 hr 24 hr 5 CLA+ T Cells Unstimulated BelowDetection Below Detection 5 CLA+ T Cells αCD3 1385.7 >1920 5 CLA− TCells Unstimulated Below Detection Below Detection 5 CLA− T Cells αCD3Below Detection Below Detection 6 CLA+ T Cells Unstimulated BelowDetection Below Detection 6 CLA+ T Cells αCD3 121.3 328.9 6 CLA− T CellsUnstimulated Below Detection Below Detection 6 CLA− T Cells αCD3 BelowDetection Below Detection

Example 2 IL-31 Involvement in Initiation and Perpetuation of ContactHyper-Sensitivity

Method I

BALB/c mice are painted on shaved mid-back with 25 μL1 of 0.5% DNFBdissolved (2,4, dinitro-fluoro-benzene, Sigma, St. Louis Mo.) inacetone:olive oil (4:1) solution using a pipettor. A vehicle controlgroup receives 25 μl of acetone:olive oil only. After 5 days, mice areanaesthetized with isofluorane in an inhalation chamber and both earpinnae of experimental and control animals are measured with anengineer's micrometer (Mitutoyo) to obtain a baseline measurement. Miceare then challenged by applying 10 μL1 of 0.25% DNFB in acetone:oliveoil (4:1) to both sides of each ear of all mice. Contacthyper-sensitivity is measured at 24 h and 48 h later as the differencebetween the right ear (challenged) and the left ear (unchallenged). Allmeasurements are done with an engineer's micrometer. Background valuesare determined by the difference in ear swelling between the challengedand unchallenged ears of naive mice.

Whole blood and serum for FACS and/or ELISA analysis are collected priorto sacrifice and ears are collected for histology.

Method II (Induces Th2 Responses)

BALB/c mice are painted on shaved mid-back with 100 ul of 0.5% FITC(fluorescein isothiocyanate) in a 1:1 solution of acetone/dibutylphthalate (MSDS available using pipettor on days 1, 2 and 8. On day 13,mice are anaesthetized with isofluorane in an inhalation chamber andboth ear pinnae of experimental and control animals are measured with anengineer's micrometer (Mitutoyo) to obtain a baseline measurement. Miceare challenged by applying 25 ul of 0.5% FITC (in 1:1 acetone/dibutylphthalate) to the dorsal surface of each ear. Contact hyper-sensitivityis measured at 24 h and 48 h later as the difference between the rightear (challenged) and the left ear (unchallenged). All measurements aredone with an engineer's micrometer. Background values are determined bythe difference in ear swelling between the challenged and unchallengedears of naive mice. Whole blood and serum for FACS and/or ELISA analysisare collected prior to sacrifice and ears are collected for histology.

Method III (Induces Th1 Responses)

BALB/c mice are painted on shaved mid-back with 25 ul of 2% oxazalone(in 4:1 acetone/olive oil) using pipettor. On day 7, mice areanaesthetized with isofluorane in an inhalation chamber and both earpinnae of experimental and control animals are measured with anengineer's micrometer (Mitutoyo) to obtain a baseline measurement. Miceare challenged by applying 8 ul of oxazalone to the dorsal surface ofeach ear. Contact hyper-sensitivity is measured at 24 h and 48 h lateras the difference between the right ear (challenged) and the left ear(unchallenged). All measurements are done with an engineer's micrometer.Background values are determined by the difference in ear swellingbetween the challenged and unchallenged ears of naive mice. Whole bloodand serum for FACS and/or ELISA analysis are collected prior tosacrifice and ears are collected for histology.

Involvement of IL-31 in the initiation and perpetuation of contacthyper-sensitivity is tested using a neutralizing antibody against IL-31both at the sensitization and challenge phases of the experiment.

Example 3 IL-31 Involvement in Atopic Dermatitis

Methods I (Sensitization of NC/Nga Mice)

Male NC/Nga mice were purchased from Charles River Laboratories, Japan.The mice were 4 weeks old on arrival and housed in SPF quarantineconditions for 4 weeks to acclimate. The mice were approximately 10-11weeks old at the start of the antigen sensitization. Mice wereanaesthetized with isofluorane and backs were shaved with electricclippers. Approximately 10 ug of Dermatophagoides pteronyssinus (Dp)(Indoor Biotechnologies, Charlottesville, Va., special order) extractwas injected intradermally at the nape of the neck 3 times per week for5 to 6 weeks until mice developed skin lesions. Control animals received10 ul PBS intradermal injections 3 times per week. The Dp extract wasprepared according to method by Matsuoka and colleagues. Matsuoka H., etal., Allergy: 58, 139 (2003). Briefly, 595 mg Dp lyophilized spentculture extract was dissolved in 12 mL sterile PBS (Gibco). Dp was mixedin a 50 mL Falcon tube on a shaking rocker for 30 minutes. The extractwas spun for 10 minutes at 2000 rpm and the supernatant was collectedand aliquoted into 1 mL cryovial tubes and stored at −20° C.

Method II (Sensitization of D011.10 Mice)

DO11.10 transgenic mice were bred from an in-house colony and werebetween 9.5 and 14 weeks old at start of antigen sensitization.Twenty-four hours prior to epicutaneous sensitization mice wereanaesthetized with isofluorane and the entire trunk (back and abdomen)of mice were shaved with electric clippers. The mice were then tapestripped with Elastin surgical tape (Johnson and Johnson) on the back.One cm² sterile gauze patches were wetted with either 500 ug ovalbumin(Calbiochem 32467) or sterile PBS (Gibco) and adhered to left backsideof mice with DuoDerm Extra Thin Dressing (ConvaTec 187932). The patchand dressing were then covered in a body wrap of the Elastin surgicaltape so mice could not remove or destroy the patches. Patches were wornfor 7 days and removed. The mice were rested for two weeks before havinganother round of epicutaneous sensitization. Mice received a total ofthree one-week sensitizations.

Results

Immunohistochemical analysis of IL-31RA expression in lesional andnon-lesional skin from dust mite sensitized NC/Nga and OVA sensitizedDO11.10 animals showed that IL-31RA is expressed by epidermalkeratinocytes in mice, however no significant difference in levels ofexpression can be found between antigen sensitized versus PBS sensitizedanimals.

Example 4 IL-31 Involvement Delayed Type Hypersenstitvity

Methods

To generate a DTH response, mice were sensitized to antigen on day 0 bysubcutaneous immunization at the base of the tail with 100 ug ovalbumin(OVA) in complete Freund's adjuvant (CFA, 50-100 μl total volume). Oneweek later mice were anesthetized with isofluorane in an inhalationchamber and both ear pinnae of experimental and control animals weremeasured with an engineer's micrometer (Mitutoyo) to obtain a baselinemeasurement. Mice were challenged intradermally with 10 ug OVA in PBS ina total volume of 10 μl into the left ear pinnae, just below the skinwithout hitting any veins. As a control, mice also received an injectionof 10 μl PBS in the right ear pinnae. In some cases, a separate controlgroup given an i.d. injection of OVA in the ear may also be treated withtopical corticosteroids as a positive control to inhibit the reaction.At 24 and 48 hr after challenge, mice were anesthetized and earthickness was measured. Results were expressed as: Specific earswelling=(24 hr measurement−0 hr measurement) for experimental ear−(24hr measurement−0 hr measurement) for negative control ear. Induration,the hallmark of DTH, is detectable by 18 hours after injection ofsensitized antigen and is maximal by 24-48 hours. The lag in the onsetof palpable induration is the reason for naming the response “delayedtype.”

Results

IL-31 transgenic mice were tested for DTH, however, due to an increasein ear thickness in un-challenged IL-31 transgenic animals, nostatistically significant difference in DTH could be determined betweenIL-31 Tg animals compared to wildtype controls. IL-31RA knockout animalswere also tested in a DTH response and no significant difference in theDTH response could be observed between receptor knockout and wildtypeanimals.

Example 5 IL-31 Involvement in Induction of the Itch Response

Methods I (IL-31 Treatment of Capsaicin Pre-Treated Mice)

Ten week old BALB/c animals (CRL) were anaesthetized and injected with along-lasting analgesic agent, bupranorphine hydrochloride,subcutaneously at 0.1 mg/kg before injection of 0.25 ml of 4 mg/mlsolution of capsaicin in 10% ethanol+10% Tween-80 in salinesubcutaneously into scruff of neck. Animals were kept anaesthetized forat least 30 min following neurotoxin treatment. Forty-eight hours later,14-day osmotic pumps were implanted subcutaneously for continuousdelivery of 20 ug/day of IL-31 for 14 days. Mice were monitored dailyfor 6 days for alopecia and pruritis using the following criteria: 0=noscratching, animal appears normal, 1=thinning of coat in small areas,scratching noted, 2=minor hair loss (small patches), scratching,3=moderate hair loss, scratching, and 4=severe hair loss, excessivescratching.

Results demonstrated that while non-capsaicin-treated mice showed a meanscratch/hairloss score of 2.625 following three days of IL-31 delivery,capsaicin-treated mice showed a significantly lower score of 1. Thusmice treated with capsaicin prior to IL-31 delivery showed both a delayin incidence of scratching and hairloss and a lower score in theintensity of scratching and hairloss over the six days of theexperiment. These data suggest that IL-31 does induce some neuronalcomponent that contributes to the alopecia and pruritis induced byIL-31. Therefore, neutralization of IL-31 may decrease the incidence andintensity of itch, and therefore dermatitis, in patients suffering fromskin disorders that involve itch.

Method II (IL-31 Treatment of Tac1 Gene Deficient Mice)

Mice that are homozygous null for the Tac1 gene express no detectiblesubstance P or neurokinin A. These mice have significantly reducednociceptive pain responses to moderate to intense stimuli and aretherefore a useful tool for studying the contribution of tachykininpeptides to pain/itch processing and inflammatory disease states. Twelveweek old, Tac1 knockout mice were implanted with 14-day osmotic pumpsdelivering 1 ug/day of IL-31 protein and observed daily for alopecia andpruritis using the following criteria: 0=no scratching, animal appearsnormal, 1=thinning of coat in small areas, scratching noted, 2=minorhair loss (small patches), scratching, 3=moderate hair loss, scratching,and 4=severe hair loss, excessive scratching.

Results of this study show that Tac1 deficient mice were lesssusceptible to IL-31 induced scratching/hairloss compared to wildtypecontrol mice. While 100% (10/10) of wildtype mice had developed evidenceof scratching and hairloss by day 6 of IL-31 treatment, only 33.3% (2/6)Tac1 deficient mice were showing signs of scratching and hairloss at thesame time-point. These data show that IL-31 induces a neuronal componentthat contributes to the scratch/hairloss phenotype in IL-31-treated miceand neutralization of IL-31 may decrease the incidence and intensity ofscratching in the context of dermatitis.

Method III (Effect of Administration of IL-31 Neutralizing Antibody onIL-31 Treated Mice)

Normal female BALB/c mice (CRL) approximately 8 to 12 weeks old wereimplanted subcutaneously with 14-day osmotic pumps (Alzet, #2002)delivering 1 ug/day mIL-31. Groups of mice received intraperitoneal(i.p.) injections of rat anti-mouse IL-31 monoclonal antibody 10 mg/kg(200 ug/mouse) twice weekly starting 1 week prior to IL-31 delivery.Control groups of mice received i.p. injections of vehicle (PBS/0.1%BSA) with the identical dosing schedules. Mice were scored daily foralopecia and pruritis using the following criteria: 0=no scratching,animal appears normal, 1=thinning of coat in small areas, scratchingnoted, 2=minor hair loss (small patches), scratching, 3=moderate hairloss, scratching, and 4=severe hair loss, excessive scratching.

In all experiments, mice treated with rat anti-mIL-31 mAb had a delay inonset of symptoms of approximately 5 to 7 days and a lower overall scorefor alopecia and pruritis. All groups of mAb treated mice (regardless ofdose frequency or concentration) developed alopecia and pruritis similarto control mice by 13 day of the study. These data suggest thatneutralization of IL-31 can delay the onset of the scratch/hairlossresponse induced by IL-31.

Example 6 Immunohistochemical (IHC) Staining of IL-31 in Skin Lesionsfrom Uninvolved Psoriatic, and Atopic Dermatitis

Uninvolved psoriatic, atopic dermatitis and normal skin were tested forthe IL-31 ligand by IHC. Positive control cells consisted of BHK cellstransfected with IL-31. Negative controls performed included: (1)un-transfected BHK cells, (2) staining representative tissues and cellswith protein A purified Normal Rabbit serum and detecting antibodybinding as usual. Antibody reagent was E5758 (Rabbit anti-huIL-31 CEE,Aff. Purified at 1.0 mg/ml). Control cells included C02-6020: BHK cellsexpressing zcytor17 Lig hu-CEE/21, and a BHK wild type. Tissues testedincluded acute atopic dermatitis skin samples, chronic atopic dermatitisskin samples, unaffected area skin samples, and normal control skinsamples and other in-house control samples.

The cells and tissues described above were fixed overnight in 10% NBFand embedded in paraffin using standard techniques.

Five μM sections were baked at 61° C. for 30 min for tissue adhesion.Slides were subsequently dewaxed in 3×5′ in xylene and rehydratedthrough graded alcohols as follows: 2×2′ in 100% EtOH, 2×2′ in X95%EtOH, 1×2′ in 70% EtOH. Slides were rinsed in dH20, and then heatinduced epitope retrieval (HIER) was performed for 20 minutes understeam followed by 20 minutes cooling to RT in 10 mM Tris, 1 mM EDTA, pH9.0

Slides were loaded onto a DakoCytomation Autostainer. Slides were rinsedwith TBS/Tween buffer (TBST), prepared as recommend by manufacturer.Endogenous biotin was blocked with a 10 minute incubation in avidinsolution, washed in TBST followed by a 10 minute incubation in biotinsolution. Slides were washed in TBST. A protein block (PBSB) (0.5%Blocking Powder in PBS, Perkin Elmer NEL700001KT.) was applied for 30minutes and rinsed off slides. The primary antibody was diluted to 500ng/ml and was applied for 60 minutes in ChemMate Antibody DilutionBuffer (part# ADB250, Ventana Medical systems).

Tissues washed twice in TBST, and then incubated 45 minutes inbiotinylated Goat anti-Rabbit Ab, 750 ng/ml in PBSB (catalog #BA-1000,Vector Labs). Slides washed twice in TBST. Vectastain Elite ABC Reagent(catalog# PK-7100, Vector Labs) was incubated for 45 minutes. Slideswashed twice in TBST. Signals were developed with DAB+ (catalog# K-3468,DakoCytomation) for 10 minutes at room temperature. Tissue slides werethen counterstained in hematoxylin (catalog# H-3401 Vector Labs),dehydrated and coverslipped in VectorMount (catalog# H-5000, VectorLabs).

Results

Cell Controls:

BHK cells transfected with IL-31 was positively stained with IL-31antibody E5758 while un-transfected cells was negative for thisantibody. The same transfected and un-transfected cells were negativewith anti-rabbit sera.

2) Atopic Dermatitis Skin Analysis:

The staining pattern for IL31 in the AD skin samples is identical tothat of psoriasis skins reported previously: keratinocyte and CD3positive T-cells stained negative for IL31. A weak but rather uniformstaining of the epithelial cells in the secretory portion of the sweatglands was present, but a strong signal was observed in the inner layerof epithelium in the duct portion. Sebaceous gland was positive forIL31. There was no difference in the IL31 staining between AD and normalskin.

Immunohistochemical (IHC) staining of uninvolved psoriatic, atopicdermatitis and normal skin showed strong staining of IL-31 in theholocrine secretion of the sebaceous glands. Considering the phenotypeof IL 31 transgenic mice, it is interesting to note that the sebaceousglands originate as an epithelial bud from the outer root sheath of hairfollicles. In addition to sebaceous glands weak but rather uniformstaining of IL-31 was observed in the epithelial cells in the secretoryportion of the sweat glands and a strong signal in the inner layer ofepithelium was observed in the duct portion of sweat glands.

Example 7 Immunohistochemical (IHC) Staining of IL-31RA in UninvolvedPsoriatic, and Atopic Dermatitis

Uninvolved psoriatic, atopic dermatitis and normal skin were tested forthe IL-31RA by IHC. Positive control cells consisted of BHK cells dualtransfected with IL-31RA and OSMR. Negative controls performed included:(1) un-transfected BHK cells, (2) staining representative tissues andcells with protein A purified Normal Rabbit serum and detecting antibodybinding as usual. Antibody reagent was E6292 (Rabbit anti-huIL-31RAs-CEEv.4 at 1.33 mg/ml). Control cells included C02-5117 BHK cells expressinghuman IL-31RA and human OSMR (Total cells in the pellet: 3.9×10⁶,vitality was >90%) and C04-1587: BHK wild type (Total cells in thepellet: 5×10⁶). Other tissues examined included: 5 Acute atopicdermatitis skin samples, 10 Chronic atopic dermatitis skin samples, 10Unaffected area skin samples, Normal control skin samples, and otherin-house skin samples.

The cells and tissues described above were fixed overnight in 10% NBFand embedded in paraffin using standard techniques.

Five μM sections were baked at 61° C. for 30 min for tissue adhesion.Slides were subsequently dewaxed in 3×5′ in xylene and rehydratedthrough graded alcohols as follows: 2×2′ in 100% EtOH, 2×2′ in X95%EtOH, 1×2′ in 70% EtOH. Slides were rinsed in dH20, and then heatinduced epitope retrieval (HIER) was performed for 20 minutes understeam followed by 20 minutes cooling to RT in 10 mM Tris, 1 mM EDTA, pH9.0

Slides were loaded onto a DakoCytomation Autostainer. Slides were rinsedwith TBS/Tween buffer (TBST), prepared as recommend by manufacturer.Endogenous biotin was blocked with a 10-minute incubation in avidinsolution, washed in TBST followed by a 10-minute incubation in biotinsolution. Slides were washed in TBST. A protein block (PBSB) (0.5%Blocking Powder in PBS, Perkin Elmer NEL700001KT.) was applied for 30minutes and rinsed off slides. Primary antibodies diluted from 665 ng/mlto 1330 ng/ml for IL31RA were applied for 60 minutes in ChemMateAntibody Dilution Buffer (part# ADB250, Ventana Medical systems).

Tissues were washed twice in TBST, and then incubated 45 minutes inbiotinylated Goat anti-Rabbit Ab, 750 ng/ml in PBSB (catalog #BA-1000,Vector Labs). Slides were washed twice in TBST. Vectastain Elite ABCReagent (catalog# PK-7100, Vector Labs) was incubated for 45 minutes.Slides were washed twice in TBST. Signals were developed with DAB+(catalog# K-3468, DakoCytomation) for 10 minutes at room temperature.Tissue slides were then counterstained in hematoxylin (catalog# H-3401Vector Labs), dehydrated and coverslipped in VectorMount (catalog#H-5000, Vector Labs).

Results are shown in Table 2.

TABLE 2 Results of IHC for IL-31RA in Skin Biopsies from Acute andUninvolved AD Compared to Normal Volunteers IL-31RA IHC CASE ID SCORE*CD3 IHC SCORE* AD-1 2-3 0-1 AD-2 2-3 2 AD-3 2-3 1-2 AD-4 3 1 AD-5 2 2UAD-1 1-2 1 UAD-2 1 0-1 UAD-3 ND ND UAD-4 ND ND UAD-5 1-2 0-1 UAD-6 2-3ND UAD-7 2 1 UAD-8 1 1 UAD-9 1-2 1 UAD-10 2 ND Normal-1 1 0-1 Normal-20-1 0-1 Normal-3 1 0-1 Abbreviations: AD: atopic dermatitis; UAD:uninvolved AD; ND: Not Done *IHC signal was scored from 0 (no signal) to4 (intense signal)

There was a slight up regulation of IL31RA in the epidermis of AD skinsamples. Possibly a small percentage of CD3 positive T-cells werepositive for IL31RA in the AD skins. There were CLA positive cells inall skin samples tested. AD skins may have more CLA positive cells thanthat of the normal or UAD samples.

IL-31RA was also expressed in the epithelial cells of eccrine sweatglands with the cuboidal epithelial cells in the secretory portion ofthe eccrine glands demonstrating slightly higher level of IL-31RAprotein compared to the duct portion.

Collectively, these data demonstrate that IL-31RA is expressed byepidermal keratinocytes from both control volunteers and AD patients.However, the levels of IL-31RA expressed on keratinocytes from AD skinbiopsies were higher than the levels observed in skin biopsies fromnormal controls, indicating a potential for increased responsiveness toIL-31 in the context of AD.

IL-31RA was also found expressed on a subset of perivascularinfiltrating cells present in skin biopsies from AD patients but was notpresent in control skin biopsies. These IL-31RA+ cells were recognizedby an antibody specific for the tissue macrophage marker CD68,indicating these cells were skin-infiltrating tissue macrophages.

Example 8 Isolation of Skin Infiltrating cells by Laser CaptureMicroscopy and Analysis of IL-31mRNA by RT-PCR

The presence of skin infiltrating T cells is a distinguishing feature inskin biopsies from AD patients compared to normal individuals. SinceIL-31 is a T cell associated cytokine, the expression of IL-31 inskin-infiltrating T cells in tissue biopsies from AD patients wasexamined. First, the presence of increased numbers of CD3+ T cells inskin tissue biopsies from AD patients compared to normal individuals wasconfirmed by IHC. See Table 2. Next, laser capture microscopy was usedto specifically isolate skin infiltrating cells for analysis of IL-31mRNA by RT-PCR. IL-31 mRNA was expressed by skin infiltrating cells fromacute AD patients. In normal tissues, infiltrating cells are notnormally found and therefore could not be tested. However, the epidermalkeratinocyte layer, which is present in both AD and normal skin, wasanalyzed for IL-31 mRNA expression and lower levels of IL-31 mRNA werefound in normal samples compared to the epidermal keratinocyte layer ofAD samples. Semi-quantitative analysis of IL-31 mRNA expression comparedto an internal control gene (HPRT) showed that although IL-31 mRNAlevels were not significantly different between AD and normal samples,there was a trend towards higher IL-31 expression in skin from ADpatients.

Example 9 IL-31 is Produced by Memory T Cells with a Skin-HomingPhenotype

Analysis of skin biopsies confirmed that the infiltrating CD3+ T cellsin the skin, which express IL-31 mRNA, express the skin-homing markercutaneous lymphocyte antigen (CLA). Of the total T cell population innormal human peripheral blood, IL-31 expression was found to be largelyrestricted to CD45RO+ memory/effector cells as opposed to theCD45RA+naïve T cell population.

In order to determine if IL-31 production was associated with CLA+skin-homing T cells, CLA+ and CLA− T cells were isolated from peripheralblood of patients diagnosed with AD and control volunteers and comparedIL-31 mRNA and protein levels following anti-CD3 plus anti-CD28stimulation. Our results indicate that IL-31 mRNA was significantlyelevated in CLA+ T cells from both AD and normal individuals at both 4 h(p0.0087 and p0.0022 CLA+ compared to CLA− for AD and normal,respectively) and 24 h (p0.0022 CLA+ compared to CLA− for both AD andnormal samples) post stimulation. Analysis of IL-31 protein levels inculture supernatants confirmed that IL-31 was produced predominantly byCLA+ T cells as there was no detectible IL-31 in culture supernatantsfrom CLA− T cells from both AD and control individuals. There were nosignificant differences in IL-31 levels between AD and normal patients.We also analysed the production of IL-31 by peripheral blood T cellsthat express other tissue-specific homing markers, such as thegut-specific homing marker α4β7, from normal volunteers. Comparison ofthe IL-31 levels produced by CLA+ T cells and α4β7+ cells demonstratedCLA+ T cells preferentially produce IL-31 compared to the α4β7+ cells(average of 34.5 pg/ml and 14.42 pg/ml IL-31, respectively).

Although both AD patients and normal controls have circulating CLA+ Tcells that express IL-31 upon activation, CLA+ T cells from AD patientsare reported to exist in a more activated state compared to cells fromnormal individuals. Consequently, the threshold of stimulation requiredfor the production of IL-31 by CLA+ T cells may differ betweendermatitis patients and control subjects. To test this hypothesis, westimulated CLA+ T cells from AD patients and control individuals withsub-optimal concentrations of anti-CD3 in the absence of anti-CD28 andanalyzed the production of IL-31 in culture supernatants at 24 h afterstimulation. Our results demonstrate that circulating CLA+ T cells fromsome AD patients produce higher levels of IL-31 compared to cells fromnormal individuals in this study with maximum levels reaching 1200pg/mL, whereas maximal detected levels in normal CLA+ supernatants wasonly 400 pg/ml and maximal detected levels for psoriasis patients was 73pg/ml at suboptimal concentrations of anti-CD3 stimulation. Five ofeleven AD patients showed IL-31 levels below the limit of detection ofour assay suggesting there might be a subset of AD patients where IL-31is produced at low levels. This may reflect variations in the stage ofdisease of our study population. Nevertheless, more than half of the ADpatients showed a trend towards higher IL-31 levels compared topsoriasis patients and normal individuals following suboptimalstimulation with anti-CD3. Since more CLA+ T cells are localized in skinof AD patients as compared to normal individuals, our studies suggestthat there is an increased potential for IL-31 activity in the AD skinmicro-environment. Thus, this study may suggest a subpopulation of ADpatients, which have more activated CLA+ T cells producing IL-31.

Example 10 Reduction of TARC and MDC in Response to Anti-Il-31 Antibodyin AD Mouse Models

Method I

Six-week old male NC/Nga mice (CRL Japan) were sensitized intradermallywith 50 μg dust mite extract (D. pteronyssinus, Indoor Biotechnologies)three times a week on the back and scored for AD-like lesions. After 5weeks of sensitization the mice were euthanized and the right ears wereexcised and placed into a single well of a 48-well culture dish(Corning) supplemented with RPMI+2% FBS (GIBCO Invitrogen). Plates wereplaced in 5% CO2 humidity controlled incubators. Supernatants werecollected after 24 hours and frozen at −20° C. until further analysis.

Method II

Twelve-week old female NC/Nga mice (CRL Japan) were sensitizedintradermally with 10 μg SEB (Toxin Technology) in the ear and on theback three times per week. The mice were scored for AD-like lesions.After 5 weeks of sensitization the mice were euthanized and 6 mm biopsypunches were taken from the injected ear of each mouse and placed into asingle well of a 48-well culture dish supplemented with RPMI+2% FBS.Plates were placed in 5% CO2 humidity controlled incubators.Supernatants were collected after 24 hours and frozen at −20° C. untilfurther analysis.

Groups of mice in both studies were treated with either a rat anti-mouseIL-31 monoclonal antibody at 10 mg/kg or vehicle, intraperitoneally twotimes each week starting after 1 to 2 weeks of sensitization.

TARC and MDC concentrations in the 24-hour supernatant samples weremeasured by conventional ELISA (R&D Systems).

TARC and MDC concentrations were lower in ear supernatants fromanti-IL-31 treated mice compared to control mice in both studies,however, these results were not statistically significant when analyzedby ANOVA, probably due to small sample size. When the data from bothexperiments is combined and analyzed there is a statisticallysignificant difference between treated groups.

1. A method of treating a patient with a condition selected from thegroup consisting of: a) prurigo nodularis; b) Cutaneous T cell Lymphoma;c) Bullous pemphigoid; d) Vitiligo; e) Acne Rosacea; and f) Sclerodermathe method comprising: administering a therapeutically effective amountof Interleukin-31RA (IL-31RA) to the patient, wherein the IL-31RAcomprises amino acid residues 20-519 of SEQ ID NO:6.
 2. The method ofclaim 1, wherein the IL-31RA is neutralizing.
 3. The method of claim 1,wherein the IL-31RA is conjugated to polyethylene glycol.
 4. The methodof claim 1, wherein the IL-31RA is conjugated to human serum albumin. 5.The method of claim 1, wherein the IL-31RA is conjugated to the Fcregion of IgG, IgA, IgD, IgM or IgE.
 6. The method of claim 1, whereinthe IL-31RA is an IL-31RA homodimer.
 7. The method of claim 1, whereinthe IL-31RA is a heterodimer with Oncostatin M receptor beta (OSMRbeta).8. The method of claim 1, wherein the IL-31RA binds with an IL-31polypeptide consisting of amino acid residues 27-164 of SEQ ID NO:2. 9.A method of treating a patient with prurigo nodularis, comprisingadministering a therapeutically effective amount of an IL-31RA to thepatient, wherein the IL-31RA comprises amino acid residues 20-519 of SEQID NO:6.
 10. The method of claim 9, wherein the IL-31RA is neutralizing.11. The method of claim 9, wherein the IL-31RA is conjugated topolyethylene glycol.
 12. The method of claim 9, wherein the IL-31RA isconjugated to human serum albumin.
 13. The method of claim 9, whereinthe IL-31RA is conjugated to the Fc region of IgG, IgA, IgD, IgM or IgE.14. The method of claim 9, wherein the IL-31RA is an IL-31RA homodimer.15. The method of claim 9, wherein the IL-31RA forms a heterodimer withOncostatin M receptor beta (OSMRbeta).
 16. The method of claim 9,wherein the IL-31RA binds with an IL-31 polypeptide consisting of aminoacid residues 27-164 of SEQ ID NO:2.
 17. A method of treating a patientwith toxic epidermal necrolysis, the method comprising administering atherapeutically effective amount of an IL-31RA to the patient, whereinthe IL-31RA comprises amino acid residues 20-519 of SEQ ID NO:6.
 18. Themethod of claim 17, wherein the IL-31RA is neutralizing.
 19. The methodof claim 17, wherein the IL-31RA is conjugated to polyethylene glycol.20. The method of claim 17, wherein the IL-31RA is conjugated to humanserum albumin.
 21. The method of claim 17, wherein the IL-31RA isconjugated to the Fc region of IgG, IgA, IgD, IgM or IgE.
 22. The methodof claim 17, wherein the IL-31RA is an IL-31RA homodimer.
 23. The methodof claim 17, wherein the IL-31RA forms a heterodimer with Oncostatin Mreceptor beta (OSMRbeta).
 24. The method of claim 17, wherein theIL-31RA binds with an IL-31 polypeptide consisting of amino acidresidues 27-164 of SEQ ID NO:2.